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1.
Ann Acad Med Singap ; 53(6): 371-385, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38979993

ABSTRACT

Introduction: Paroxysmal nocturnal haemoglobinuria (PNH) is a rare haematologic disease characterised by intravascular haemolysis, thrombophilia and bone marrow failure. There is a lack of established clinical guidance on the screening, diagnosis and manage-ment of PNH in Singapore. A relatively low level of awareness among healthcare professionals regarding PNH manifestations further contributes to diagnostic delays. Additionally, limited access to complement inhibitors, like eculizumab, may delay treatment and impact patient outcomes. Method: Nine haematologists from different institu-tions in Singapore convened to formulate evidence-based consensus recommendations for optimising the diagnosis and management of patients with PNH and improving access to novel treatments. The experts reviewed the existing literature and international guidelines published from January 2010 to July 2023, focusing on 7 clinical questions spanning PNH screening, diagnostic criteria, investigations, treatment and monitoring of subclinical and classic disease, PNH with underlying bone marrow disorders, and PNH in pregnancy. A total of 181 papers were reviewed to formulate the statements. All experts voted on the statements via 2 rounds of Delphi and convened for an expert panel discussion to finetune the recommendations. Results: Sixteen statements have been formulated for optimising the screening, diagnosis and management of PNH. Upon confirmation of PNH diagnosis, individuals with active haemolysis and/or thrombosis should be considered for anti-complement therapy, with eculizumab being the only approved drug in Singapore. Conclusion: The current recommendations aim to guide the clinicians in optimising the screening, diagnosis and management of PNH in Singapore.


Subject(s)
Antibodies, Monoclonal, Humanized , Hemoglobinuria, Paroxysmal , Female , Humans , Male , Pregnancy , Antibodies, Monoclonal, Humanized/therapeutic use , Complement Inactivating Agents/therapeutic use , Consensus , Delphi Technique , Hemoglobinuria, Paroxysmal/diagnosis , Hemoglobinuria, Paroxysmal/therapy , Pregnancy Complications, Hematologic/diagnosis , Pregnancy Complications, Hematologic/therapy , Pregnancy Complications, Hematologic/drug therapy , Singapore
2.
Int J Mol Sci ; 25(13)2024 Jun 27.
Article in English | MEDLINE | ID: mdl-39000133

ABSTRACT

There is growing evidence that inflammation impairs erythrocyte structure and function. We assessed the impact of mild systemic inflammation on erythrocyte fragility in three different settings. In order to investigate causation, erythrocyte osmotic fragility was measured in mice challenged with a live attenuated bacterial strain to induce low-grade systemic inflammation; a significant increase in erythrocyte osmotic fragility was observed. To gather evidence that systemic inflammation is associated with erythrocyte fragility in humans, two observational studies were conducted. First, using a retrospective study design, the relationship between reticulocyte-based surrogate markers of haemolysis and high-sensitivity C-reactive protein was investigated in 9292 healthy participants of the UK Biobank project. Secondly, we prospectively assessed the relationship between systemic inflammation (measured by the urinary neopterin/creatinine ratio) and erythrocyte osmotic fragility in a mixed population (n = 54) of healthy volunteers and individuals with long-term medical conditions. Both human studies were in keeping with a relationship between inflammation and erythrocyte fragility. Taken together, we conclude that mild systemic inflammation increases erythrocyte fragility and may contribute to haemolysis. Further research is needed to assess the molecular underpinnings of this pathway and the clinical implications in inflammatory conditions.


Subject(s)
C-Reactive Protein , Erythrocytes , Hemolysis , Inflammation , Osmotic Fragility , Humans , Inflammation/blood , Inflammation/metabolism , Erythrocytes/metabolism , Male , Animals , Mice , Female , Middle Aged , C-Reactive Protein/metabolism , Aged , Adult , Retrospective Studies , Biomarkers/urine , Biomarkers/blood , Neopterin/urine , Neopterin/blood
3.
Vox Sang ; 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38970298

ABSTRACT

BACKGROUND AND OBJECTIVES: To investigate the prevalence, genotype and haematological characteristics of glucose-6-phosphate dehydrogenase (G6PD) deficiency in the blood donor population of Wuxi area (Jiangsu Province, China) and to assess the impact of their red blood cell (RBC) units on clinical transfusion. MATERIALS AND METHODS: We conducted genotyping and large-scale screening for G6PD enzyme activity in the blood donors of Wuxi City. In addition, we assessed the haematological parameters of G6PD-deficient and non-deficient blood donors, and investigated the adverse transfusion reactions in patients transfused with G6PD-deficient blood. RESULTS: We investigated 17,113 blood donors, among whom 44 (0.26%) were tested positive for G6PD deficiency. We identified 40 G6PD gene variants, among which c.1388G>A, c.1376G>T, c.1024C>T and c.95A>G were common. In addition, we identified two novel G6PD gene variants, c.1312G>A and c.1316G>A. The G6PD-deficient and non-deficient blood samples showed a significant difference in the RBC, mean corpuscular volume (MCV), mean corpuscular Hb (MCH), RBC distribution width, total bilirubin (TBIL), direct bilirubin (DBIL) and indirect bilirubin (IBIL) values. However, the two samples showed no significant difference in the haemolysis rate at the end of the storage period. Finally, transfusion with G6PD-deficient RBC units did not lead to any adverse transfusion reactions. CONCLUSION: The positive rate of G6PD deficiency in the blood donor population of Wuxi City is 0.26%, and the genetic variants identified in this population are consistent with the common genetic variants observed in the Chinese population. Blood centres can establish a database on G6PD-deficient blood donors and mark their RBC units to avoid their use for special clinical patients.

4.
Cureus ; 16(5): e60534, 2024 May.
Article in English | MEDLINE | ID: mdl-38887323

ABSTRACT

Introduction Periodontitis, a persistent inflammatory condition, impacts the tissues supporting teeth. Beyond mechanically eradicating the biofilm, additional host-modulating agents can aid in the treatment of periodontitis. Among these, gels are a very popular choice for use in the field of dentistry as these systems boast high biocompatibility and bioadhesiveness. These qualities make them easily administered and fabricated. They are typically placed into the periodontal site via wide-port needle syringes. Many investigations have demonstrated that hydrogels possess the ability for controlled drug release and aid in periodontal wound healing. Hence, this study aimed to develop a ferulic acid hydrogel and assess its effectiveness for managing periodontitis. Materials and methods Ferulic acid hydrogel was prepared followed by haemolysis assay and biocompatibility assay. After the in vitro analysis, a clinical trial was conducted: 20 patients were divided into Group A (comprising patients in whom scaling and root planing (SRP) was done) and Group B (comprising patients in whom SRP along with hydrogel application was done). Each patient's pocket depth (PD), clinical attachment loss (CAL), gingival index (GI), and plaque index (PI) were recorded at baseline and at three months. Intergroup and intragroup comparisons of the parameters were made. Results Ferulic acid hydrogels exhibit a minimal ratio of red blood cell destruction, indicating their low haemolytic activity. Beyond 94 hours, ferulic acid hydrogel demonstrates minimal toxicity towards human fibroblasts, suggesting it has good biocompatibility. When clinical parameters were compared after three months of treatment with SRP alone, significant reductions were observed in all parameters. However, when hydrogel application was done along with SRP, greater reduction was seen in terms of all clinical parameters indicating the efficacy of the ferulic acid hydrogel as an adjunct.  Conclusion Ferulic acid has distinct haemolytic activity as well as good biocompatibility. Its use also led to a considerable reduction in all clinical parameters, necessitating its role as a local drug delivery agent in the treatment of periodontitis.

5.
Br J Haematol ; 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38831605

ABSTRACT

The degree of anaemia in sickle cell disease (SCD) is a well-known contributor to morbidity and mortality. We aimed to explore the factors affecting haemoglobin (Hb) level in African SCD patients, considering haemolysis biomarkers (LDH and bilirubin level, and reticulocyte count), leucocyte and platelet counts and socio-demographic characteristics (gender, age group, country of residence and BMI). The research was part of the CADRE multinational cohort and involved 3699 SCD patients living in Mali, Senegal, Ivory Coast, Democratic Republic of Congo, Gabon and Cameroon: 2936 SS/Sß0, 587 SC and 176 Sß + patients with median Hb level of 8, 11.3 and 11.2 g/dL respectively (p < 0.001). In multivariate analysis conducted in 1394 SS/Sß0 patients, living in Cameroon, female gender, lower BMI, higher haemolysis markers (especially LDH) and higher leucocyte and platelet counts were independently associated with lower Hb level (all p < 0.05). In 497 SC and 156 Sß + patients, female gender (p < 0.001), lower BMI (p < 0.05) and higher platelet counts (p < 0.001) were independently associated with lower Hb level. Anaemia in African SCD patients is not only associated with haemolysis but also with the country of residence, lower BMI and leucocyte or platelet counts which might reflect inflammation related to infectious burden in the region.

6.
Vet Med Sci ; 10(4): e1451, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38818774

ABSTRACT

The aim of this study is to describe a case of haemoglobinuria in a cat after near-drowning. A 6-year-old male neutered domestic short hair cat weighing 6.5 kg with a pre-existing seizure disorder presented to an emergency hospital after near-drowning in a swimming pool during a seizure episode. On presentation, the patient was obtunded, dyspnoeic, bradycardic and hypothermic. Imaging revealed evidence of severe bilateral pulmonary infiltrates. Treatment with intravenous diazepam, amoxicillin, fluid therapy, active warming and oxygen therapy was administered. The cat developed haemoglobinuria approximately 6 h after nearly drowning. Despite improvements in mentation, pulse quality and heart rate, respiratory compromise and poor oxygen saturation persisted, prompting euthanasia approximately 10 h after admission. To the author's knowledge, this is the first reported clinical case of haemoglobinuria following near-drowning in veterinary medicine.


Subject(s)
Cat Diseases , Hemoglobinuria , Cats , Animals , Male , Cat Diseases/etiology , Cat Diseases/diagnosis , Hemoglobinuria/veterinary , Hemoglobinuria/etiology
7.
Colloids Surf B Biointerfaces ; 239: 113932, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38749165

ABSTRACT

Quaternary ammonium salts (QAS) are widely used in medicine, industry and agriculture as disinfectants, biocides, and fungicides. QAS have the ability to coat various surfaces, prevent adhesion of microorganisms to them and inhibit the formation of biofilm. A group of surfactants derived from benzoic acid with different chemical structures was tested: monomeric QAS with different alkyl chain lengths (C12, C14, C16), gemini QAS containing 12-carbon alkyl chains and linkers of various lengths (3,4,6 methylene groups), as well as multifunctional QAS. Among the tested surfactants, monomeric QAS showed the highest bactericidal and fungicidal activity. All three groups of tested compounds inhibited the filamentation of C. albicans. The best antimicrobial activity was demonstrated by the monomeric surfactant C12AA, while the multifunctional equivalent (2xC12AA) was characterized by good anti-adhesive activity. All tested compounds are non-mutagenic and cause low hemolysis of sheep erythrocytes. Multifunctional and gemini surfactants are also non-toxic.


Subject(s)
Candida albicans , Hemolysis , Microbial Sensitivity Tests , Surface-Active Agents , Surface-Active Agents/pharmacology , Surface-Active Agents/chemistry , Surface-Active Agents/chemical synthesis , Sheep , Animals , Candida albicans/drug effects , Hemolysis/drug effects , Erythrocytes/drug effects , Biofilms/drug effects , Anti-Infective Agents/pharmacology , Anti-Infective Agents/chemistry , Anti-Infective Agents/chemical synthesis , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/chemical synthesis , Quaternary Ammonium Compounds/chemistry , Quaternary Ammonium Compounds/pharmacology , Quaternary Ammonium Compounds/chemical synthesis , Antifungal Agents/pharmacology , Antifungal Agents/chemical synthesis , Antifungal Agents/chemistry
8.
Clin Chem Lab Med ; 62(8): 1538-1547, 2024 Jul 26.
Article in English | MEDLINE | ID: mdl-38581294

ABSTRACT

AIM: Blood Sampling Guidelines have been developed to target European emergency medicine-related professionals involved in the blood sampling process (e.g. physicians, nurses, phlebotomists working in the ED), as well as laboratory physicians and other related professionals. The guidelines population focus on adult patients. The development of these blood sampling guidelines for the ED setting is based on the collaboration of three European scientific societies that have a role to play in the preanalytical phase process: EuSEN, EFLM, and EUSEM. The elaboration of the questions was done using the PICO procedure, literature search and appraisal was based on the GRADE methodology. The final recommendations were reviewed by an international multidisciplinary external review group. RESULTS: The document includes the elaborated recommendations for the selected sixteen questions. Three in pre-sampling, eight regarding sampling, three post-sampling, and two focus on quality assurance. In general, the quality of the evidence is very low, and the strength of the recommendation in all the questions has been rated as weak. The working group in four questions elaborate the recommendations, based mainly on group experience, rating as good practice. CONCLUSIONS: The multidisciplinary working group was considered one of the major contributors to this guideline. The lack of quality information highlights the need for research in this area of the patient care process. The peculiarities of the emergency medical areas need specific considerations to minimise the possibility of errors in the preanalytical phase.


Subject(s)
Blood Specimen Collection , Emergency Service, Hospital , Humans , Blood Specimen Collection/standards , Blood Specimen Collection/methods , Emergency Medicine/standards , Pre-Analytical Phase/standards , Europe , Societies, Medical , Chemistry, Clinical/standards , Chemistry, Clinical/methods
9.
Pathology ; 56(4): 565-570, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38480050

ABSTRACT

Discerning the type of autoimmune haemolytic anaemia (AIHA) is crucial for transfusion support and initiation of treatment. This study aimed to establish the clinical profile and serological character of red cell autoantibodies and to investigate the relationship with haemolysis in AIHA patients who were direct antiglobulin test (DAT)-positive. A total of 59 DAT-positive AIHA patients were included in this study. Clinical, laboratory and serological findings were evaluated to find the gradation of haemolysis and to investigate its correlation with age, sex, type of autoantibody and level of autoantibody. Study findings revealed that most patients (89.8%) had haemolysis, wherein moderate haemolysis (67.8%) was predominant. Weakness, palpitations, fever, pallor, tachycardia and splenomegaly were common among patients with severe and moderate haemolysis. The majority (66.1%) had an associated disorder. Warm autoantibody was the most common, followed by cold and mixed cases. The severity of haemolysis correlated strongly with the strength of the DAT reaction (Cramer V 0.636, p<0.001). These findings may be useful to clinicians while determining a treatment plan. The direct relationship between severity of haemolysis and strength of DAT needs further exploration in a large population to establish whether it can be used as a tool to formulate a treatment plan when assessing AIHA patients in low resourced countries.


Subject(s)
Anemia, Hemolytic, Autoimmune , Autoantibodies , Coombs Test , Hemolysis , Humans , Anemia, Hemolytic, Autoimmune/blood , Anemia, Hemolytic, Autoimmune/diagnosis , Anemia, Hemolytic, Autoimmune/immunology , Male , Female , Bangladesh/epidemiology , Autoantibodies/blood , Adult , Adolescent , Child , Young Adult , Child, Preschool , Middle Aged
10.
Front Physiol ; 15: 1321468, 2024.
Article in English | MEDLINE | ID: mdl-38550255

ABSTRACT

Space travel exposes astronauts to several environmental challenges, including microgravity and radiation exposure. To overcome these stressors, the body undergoes various adaptations such as cardiovascular deconditioning, fluid shifts, metabolic changes, and alterations in the state of the bone marrow. Another area of concern is the potential impact of these adaptations on erythrocyte and haemoglobin concentrations, which can lead to what is commonly referred to as space anaemia or microgravity-induced anaemia. It is known that anaemia may result in impaired physical and cognitive performance, making early detection and management crucial for the health and wellbeing of astronauts during extended space missions. However, the effects and mechanisms of space anaemia are not fully understood, and research is underway to determine the extent to which it poses a challenge to astronauts. Further research is needed to clarify the long-term effects of microgravity on the circulatory system and to investigate possible solutions to address spaceflight-induced anaemia. This article reviews the potential link between spaceflight and anaemia, based on existing evidence from simulated studies (e.g., microgravity and radiation studies) and findings from spaceflight studies (e.g., International Space Station and space shuttle missions).

11.
J Med Case Rep ; 18(1): 163, 2024 Mar 19.
Article in English | MEDLINE | ID: mdl-38500232

ABSTRACT

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.


Subject(s)
Acalypha , Glucosephosphate Dehydrogenase Deficiency , Methemoglobinemia , Plants, Medicinal , Adult , Child , Female , Humans , Acalypha/adverse effects , Glucosephosphate Dehydrogenase Deficiency/complications , Hemolysis , Methemoglobinemia/chemically induced , Oxidative Stress , Male
13.
Br J Haematol ; 204(5): 2040-2048, 2024 May.
Article in English | MEDLINE | ID: mdl-38415930

ABSTRACT

The hexokinase (HK) enzyme plays a key role in red blood cell energy production. Hereditary non-spherocytic haemolytic anaemia (HNSHA) caused by HK deficiency is a rare disorder with only 12 different disease-associated variants identified. Here, we describe the clinical features and genotypes of four previously unreported patients with hexokinase 1 (HK1)-related HNSHA, yielding two novel truncating HK1 variants. The patients' phenotypes varied from mild chronic haemolytic anaemia to severe infantile-onset transfusion-dependent anaemia. Three of the patients had mild haemolytic disease caused by the common HK1 promoter c.-193A>G variant combined with an intragenic HK1 variant, emphasizing the importance of including this promoter variant in the haemolytic disease gene panels. HK activity was normal in a severely affected patient with a homozygous HK1 c.2599C>T, p.(His867Tyr) variant, but the affinity for ATP was reduced, hampering the HK function. In cases of HNSHA, kinetic studies should be considered in the functional studies of HK. We reviewed the literature of previously published patients to provide better insight into this rare disease and add to the understanding of genotype-phenotype correlation.


Subject(s)
Anemia, Hemolytic, Congenital Nonspherocytic , Hexokinase , Promoter Regions, Genetic , Humans , Hexokinase/genetics , Hexokinase/deficiency , Female , Male , Anemia, Hemolytic, Congenital Nonspherocytic/genetics , Infant , Alleles , Child, Preschool , Phenotype , Child , Genotype
14.
Elife ; 132024 Feb 07.
Article in English | MEDLINE | ID: mdl-38323802

ABSTRACT

A single 300 mg dose of tafenoquine, in combination with chloroquine, is currently approved in several countries for the radical cure (prevention of relapse) of Plasmodium vivax malaria in patients aged ≥16 years. Recently, however, Watson et al. suggested that the approved dose of tafenoquine is insufficient for radical cure, and that a higher 450 mg dose could reduce P. vivax recurrences substantially (Watson et al., 2022). In this response, we challenge Watson et al.'s assertion based on empirical evidence from dose-ranging and pivotal studies (published) as well as real-world evidence from post-approval studies (ongoing, therefore currently unpublished). We assert that, collectively, these data confirm that the benefit-risk profile of a single 300 mg dose of tafenoquine, co-administered with chloroquine, for the radical cure of P. vivax malaria in patients who are not G6PD-deficient, continues to be favourable where chloroquine is indicated for P. vivax malaria. If real-world evidence of sub-optimal efficacy in certain regions is observed or dose-optimisation with other blood-stage therapies is required, then well-designed clinical studies assessing safety and efficacy will be required before higher doses are approved for clinical use.


Subject(s)
Aminoquinolines , Antimalarials , Malaria, Vivax , Humans , Antimalarials/therapeutic use , Chloroquine/therapeutic use , Malaria, Vivax/drug therapy , Primaquine/therapeutic use , Meta-Analysis as Topic
15.
Elife ; 132024 Feb 07.
Article in English | MEDLINE | ID: mdl-38323801

ABSTRACT

In our recent paper on the clinical pharmacology of tafenoquine (Watson et al., 2022), we used all available individual patient pharmacometric data from the tafenoquine pre-registration clinical efficacy trials to characterise the determinants of anti-relapse efficacy in tropical vivax malaria. We concluded that the currently recommended dose of tafenoquine (300 mg in adults, average dose of 5 mg/kg) is insufficient for cure in all adults, and a 50% increase to 450 mg (7.5 mg/kg) would halve the risk of vivax recurrence by four months. We recommended that clinical trials of higher doses should be carried out to assess their safety and tolerability. Sharma and colleagues at the pharmaceutical company GSK defend the currently recommended adult dose of 300 mg as the optimum balance between radical curative efficacy and haemolytic toxicity (Sharma et al., 2024). We contend that the relative haemolytic risks of the 300 mg and 450 mg doses have not been sufficiently well characterised to justify this opinion. In contrast, we provided evidence that the currently recommended 300 mg dose results in sub-maximal efficacy, and that prospective clinical trials of higher doses are warranted to assess their risks and benefits.


Subject(s)
Aminoquinolines , Antimalarials , Malaria, Vivax , Adult , Humans , Antimalarials/therapeutic use , Hemolysis , Malaria, Vivax/drug therapy , Primaquine/therapeutic use , Prospective Studies , Meta-Analysis as Topic
16.
Ann Clin Biochem ; 61(2): 107-114, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37542363

ABSTRACT

BACKGROUND: Although venipuncture is minimally invasive, and is the most frequently performed medical procedure, it carries the small risk of causing persistent pain, including nerve damage. Recently, our hospital stopped using 22-gauge needles for venipuncture in outpatients and switched to using only 23- and 25-gauge needles. We investigated the impact of using only the finer needles on the incidence of persistent or neuropathic pain and the prevalence of haemolysis, as well as the impact of haemolysis associated with the needle change on other laboratory data. METHODS: We retrospectively collected and analysed data on venipuncture-associated pain complaints made during the 1-year period prior and 1-year period after the change in needles, as well as the frequency of haemolysis before and after the change. We also focused on 90 cases that showed significant haemolysis after the needle change and compared the serum aspartate aminotransferase, lactate dehydrogenase, and potassium levels before and after the needle change. RESULTS: The incidence of persistent pain was significantly reduced from 1 in 10,825 venipunctures before the change to 1 in 29,747 venipunctures after the change. Notably, no patients experienced neuropathic pain after the change. However, the prevalence of haemolysis was significantly increased. Additionally, the serum aspartate aminotransferase, lactate dehydrogenase, and potassium levels were significantly elevated in the cases that showed moderate to gross haemolysis after the needle change. CONCLUSION: Using finer needles involves both advantages and disadvantages, and careful consideration is needed to determine which type of needle is in the best interests of the patient.


Subject(s)
Neuralgia , Phlebotomy , Humans , Phlebotomy/adverse effects , Retrospective Studies , Hemolysis , Aspartate Aminotransferases , Lactate Dehydrogenases , Potassium
17.
Immunology ; 171(2): 181-197, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37885279

ABSTRACT

Haemolytic disorders, such as sickle cell disease, are accompanied by the release of high amounts of labile heme into the intravascular compartment resulting in the induction of proinflammatory and prothrombotic complications in affected patients. In addition to the relevance of heme-regulated proteins from the complement and blood coagulation systems, activation of the TLR4 signalling pathway by heme was ascribed a crucial role in the progression of these pathological processes. Heme binding to the TLR4-MD2 complex has been proposed recently, however, essential mechanistic information of the processes at the molecular level, such as heme-binding kinetics, the heme-binding capacity and the respective heme-binding sites (HBMs) is still missing. We report the interaction of TLR4, MD2 and the TLR4-MD2 complex with heme and the consequences thereof by employing biochemical, spectroscopic, bioinformatic and physiologically relevant approaches. Heme binding occurs transiently through interaction with up to four HBMs in TLR4, two HBMs in MD2 and at least four HBMs in their complex. Functional studies highlight that mutations of individual HBMs in TLR4 preserve full receptor activation by heme, suggesting that heme interacts with TLR4 through different binding sites independently of MD2. Furthermore, we confirm and extend the major role of TLR4 for heme-mediated cytokine responses in human immune cells.


Subject(s)
Signal Transduction , Toll-Like Receptor 4 , Humans , Toll-Like Receptor 4/metabolism , Binding Sites , Cytokines/metabolism , Lymphocyte Antigen 96/metabolism , Lipopolysaccharides
18.
Food Chem ; 440: 138281, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38160597

ABSTRACT

Oxidative/nitrosative damage takes part in chronic disease development, which generates an urgent need for intervention and better therapies to manage them. The scientific community has demanded easy-to-run, cheap, and reliable methods for cellular antioxidant activity assays. This work standardised and validated an erythrocyte cellular antioxidant activity and membrane protection/injury (HERYCA-P) protocol to study food-derive extracts. The method measures intracellular reactive oxygen species (ROS) generation, lipoperoxidation, and haemolysis induced by 2,2'-azobis(2-amidinopropane) dihydrochloride. Quercetin decreased ROS generation by 50.4% and haemolysis by 2.2%, while ascorbic acid inhibited lipid peroxidation by 40.1%. Total phenolic contents of teas were correlated with decreased ROS generation (r = -0.924), lipoperoxidation (r = -0.951), and haemolysis (r = -0.869). The erythrocyte ROS generation and lipoperoxidation were also associated with CUPRAC (r = -0.925; r = -0.951) and hydroxyl radical scavenging activity (r = -0.936; r = -0.949). The precision rates of antioxidant standards and tea samples were below 15%. HERYCA-P is feasible as a complementary antioxidant assay for food matrices.


Subject(s)
Antioxidants , Hemolysis , Humans , Antioxidants/pharmacology , Reactive Oxygen Species , Erythrocytes , Oxidative Stress , Lipid Peroxidation , Phenols/pharmacology , Plant Extracts/pharmacology
19.
J Matern Fetal Neonatal Med ; 36(2): 2227910, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38092424

ABSTRACT

BACKGROUND: Use of Direct Antiglobulin test (DAT) in management of neonatal hyperbilirubinemia is conflicting. OBJECTIVE: whether strength of positive DAT predicts the need for phototherapy, duration of phototherapy and need for major interventions. METHODS: We retrospectively collected data on all DAT positive neonates with birth gestational age ≥32 weeks over six years (2014-2019). Data regarding blood group, DAT and clinical details were obtained from a hospital database. We also collected data on serial hemoglobin and other relevant laboratory parameters. We also collected data on infants receiving major interventions such as exchange transfusion, in-utero transfusion, immunoglobulins, and postnatal transfusion for the duration of the study period. All of these infants were electronically followed up for a period of 6 weeks. This study was approved by institutional audit authority. All the statistics were performed using SPSS software. RESULTS: Out of 1285 DAT tests performed, only 91 infants were positive (7%), and 78 DAT positive infants were available for analysis. There were 54 infants with DAT (1+), 15 infants with DAT (2+), 7 infants with DAT (3+) and 2 infants with DAT (4+). There was no significant statistical difference in terms of need for phototherapy, duration of phototherapy, need for major interventions and hemoglobin levels at different time points between the groups (DAT 1+ Vs DAT ≥2+; DAT ≤2+ Vs DAT >2). A Total of 10 infants received major intervention, with one infant receiving all three interventions (DAT 3+ with significant maternal antibodies), 2 additional infants (both DAT1+) received exchange transfusion, 6 additional infants received immunoglobulin (2 infants: DAT 2+; 4 infants: DAT 1+) and one additional infant (DAT 1+) with significant maternal antibodies received a postnatal transfusion. CONCLUSION: Strength of a DAT did not predict the need for phototherapy, duration of phototherapy, and the need for major hemolysis related intervention in the first 6 weeks of life.


Subject(s)
Hyperbilirubinemia, Neonatal , Infant, Newborn , Infant , Humans , Retrospective Studies , Coombs Test , Hyperbilirubinemia, Neonatal/therapy , Phototherapy , Hemoglobins
20.
Arch Microbiol ; 206(1): 45, 2023 Dec 28.
Article in English | MEDLINE | ID: mdl-38153526

ABSTRACT

An aerobic, haemolytic, Gram-negative and rod-shaped bacterial strain ZY171148T was isolated from the lung of a dead goat with respiratory disease in Southwest China. The strain grew at 24-39 °C, at pH 6.0-9.0 and in the presence of 0.5-2.0% (w/v) NaCl. Phylogenetic analysis of 16S rRNA gene sequences showed that the strain belongs to the genus Moraxella. The nucleotide sequence similarity analysis of the 16S rRNA gene showed that the strain has the highest similarity of 98.1% to Moraxella (M.) caprae ATCC 700019 T. Phylogenomic analysis of 800 single-copy protein sequences indicated that the strain is a member of the genus Moraxella and forms a separated branch on the Moraxella phylogenetic tree. The strain exhibited the highest orthologous average nucleotide identity (OrthoANI) and average amino acid identity (AAI) values of 77.0 and 77.9% to M. nasibovis CCUG 75921T and M. ovis CCUG 354T, respectively. The strain shared the highest digital DNA-DNA hybridization (dDDH) value of 26.2% to M. osloensis CCUG 350T. The genome G + C content of strain ZY171148T was 42.6 mol%. The strain had C18:1 ω9c (41.7%), C18:0 (11.2%), C16:0 (14.1%) and C12:0 3OH (9.7%) as the predominant fatty acids and CoQ-8 as the major respiratory quinone. The strain contained phosphatidylglycerol, phosphatidylethanolamine, cardiolipin, dilysocardiolipin, monolysocardiolipin and phosphatidic acid as the major polar lipids. ß-haemolysis was observed on Columbia blood agar. All results confirmed that strain ZY171148T represents a novel species of the genus Moraxella, for which the name Moraxella haemolytica sp. nov. is proposed, with strain ZY171148T = CCTCC AB 2021471T = CCUG 75920T as the type strain.


Subject(s)
Goats , Respiratory Tract Diseases , Animals , Sheep , Phylogeny , RNA, Ribosomal, 16S/genetics , Moraxella/genetics , DNA
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