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1.
BMJ Case Rep ; 14(9)2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34521738

RESUMO

Neonatal hyperbilirubinaemia is a very common entity witnessed in most of the newborns. Rarely are there events where the bilirubin levels reach extreme values mandating invasive therapy. Unconjugated hyperbilirubinaemia when solely present is easy to manage and diagnose the common aetiological factors associated with it. The issue arises when we come across a mixed picture of conjugated with unconjugated hyperbilirubinaemia and puts us in a dilemma as to what are we treating. Our case highlights a similar picture where we witnessed the highest documented levels of total bilirubin but to our surprise the major component of which was direct bilirubin. This report takes us through the differentials which were ruled out and our management strategies for solving this rare mystery.


Assuntos
Colestase , Hiperbilirrubinemia Neonatal , Icterícia Neonatal , Bilirrubina , Colestase/diagnóstico , Colestase/etiologia , Hemólise , Humanos , Hiperbilirrubinemia Neonatal/diagnóstico , Hiperbilirrubinemia Neonatal/etiologia , Recém-Nascido
2.
Am J Case Rep ; 22: e932378, 2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34453029

RESUMO

BACKGROUND Envenomation from the brown recluse spider (Loxosceles reclusa) is described to cause both local and systemic symptoms. We report a case of an adolescent boy who developed severe systemic loxoscelism, and his clinical course was complicated by myocarditis, which has not been previously reported in association with loxoscelism. CASE REPORT A 16-year-old boy presented with non-specific symptoms and forearm pain following a suspected spider bite, which subsequently evolved into a necrotic skin lesion. During his clinical course, he developed a characteristic syndrome of systemic loxoscelism with hemolysis, disseminated intravascular coagulopathy, and severe systemic inflammatory response syndrome, necessitating transfer to the Intensive Care Unit. The diagnosis was confirmed with an enzyme-linked immunosorbent assay that detected Loxosceles venom in the wound. Additionally, he developed pulmonary edema and cardiogenic shock secondary to myocarditis, which was confirmed with cardiac magnetic resonance imaging. Steroids and plasmapheresis were initiated to manage the severe inflammatory syndrome, and the myocarditis was treated with intravenous immunoglobulins, resulting in resolution of symptoms and improvement of cardiac function. CONCLUSIONS This is the first reported case of myocarditis associated with loxoscelism, providing evidence for Loxosceles toxin-associated cardiac injury, which has been previously described in animal models only. Furthermore, this case provides further support for the use of confirmatory testing in the clinical diagnosis of loxoscelism.


Assuntos
Miocardite , Dermatopatias , Picaduras de Aranhas , Adolescente , Animais , Aranha Marrom Reclusa , Hemólise , Humanos , Masculino , Miocardite/diagnóstico , Miocardite/etiologia , Picaduras de Aranhas/complicações , Picaduras de Aranhas/diagnóstico
3.
Int J Mol Sci ; 22(16)2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34445550

RESUMO

Within-host adaptation is a typical feature of chronic, persistent Staphylococcus aureus infections. Research projects addressing adaptive changes due to bacterial in-host evolution increase our understanding of the pathogen's strategies to survive and persist for a long time in various hosts such as human and bovine. In this study, we investigated the adaptive processes of S. aureus during chronic, persistent bovine mastitis using a previously isolated isogenic strain pair from a dairy cow with chronic, subclinical mastitis, in which the last variant (host-adapted, Sigma factor SigB-deficient) quickly replaced the initial, dominant variant. The strain pair was cultivated under specific in vitro infection-relevant growth-limiting conditions (iron-depleted RPMI under oxygen limitation). We used a combinatory approach of surfaceomics, molecular spectroscopic fingerprinting and in vitro phenotypic assays. Cellular cytotoxicity assays using red blood cells and bovine mammary epithelial cells (MAC-T) revealed changes towards a more cytotoxic phenotype in the host-adapted isolate with an increased alpha-hemolysin (α-toxin) secretion, suggesting an improved capacity to penetrate and disseminate the udder tissue. Our results foster the hypothesis that within-host evolved SigB-deficiency favours extracellular persistence in S. aureus infections. Here, we provide new insights into one possible adaptive strategy employed by S. aureus during chronic, bovine mastitis, and we emphasise the need to analyse genotype-phenotype associations under different infection-relevant growth conditions.


Assuntos
Adaptação Fisiológica , Hemólise , Adaptação ao Hospedeiro , Glândulas Mamárias Animais/patologia , Mastite Bovina/patologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/patogenicidade , Animais , Apoptose , Bovinos , Feminino , Glândulas Mamárias Animais/microbiologia , Mastite Bovina/microbiologia , Fenótipo
4.
ACS Appl Mater Interfaces ; 13(33): 38947-38958, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34433245

RESUMO

Although dressing blood-contacting devices with robust and synergistic antibacterial and antithrombus properties has been explored for several decades, it still remains a great challenge. In order to endow materials with remarkable antibacterial and antithrombus abilities, a stable and antifouling hydrogel coating was developed via surface-initiated polymerization of sulfobetaine methacrylate and acrylic acid on a polymeric substrate followed by embedding of antimicrobial peptides (AMPs), including WR (sequence: WRWRWR-NH2) or Bac2A (sequence: RLARIVVIRVAR-NH2) AMPs. The chemical composition of the AMP-embedded hydrogel coating was determined through XPS, zeta potential, and SEM-EDS measurements. The AMP-embedded antifouling hydrogel coating showed not only good hemocompatibility but also excellent bactericidal and antiadhesion properties against Gram-positive and Gram-negative bacteria. Moreover, the hydrogel coating could protect the AMPs with long-term bioactivity and cover the positive charge of the dotted distributed AMPs, which in turn well retained the hemocompatibility and antifouling capacity of the bulk hydrogels. Furthermore, the microbiological results of animal experiments also verified the anti-infection performance in vivo. Histological and immunological data further indicated that the hydrogel coating had an excellent anti-inflammatory function. Therefore, the present study might provide a promising approach to prevent bacterial infections and thrombosis in clinical applications of blood-contacting devices and related implants.


Assuntos
Antibacterianos/química , Materiais Revestidos Biocompatíveis/química , Fibrinolíticos/química , Hidrogéis/química , Proteínas Citotóxicas Formadoras de Poros/química , Resinas Acrílicas/química , Antibacterianos/farmacologia , Bandagens , Sangue/metabolismo , Sobrevivência Celular , Materiais Revestidos Biocompatíveis/metabolismo , Eritrócitos , Fibrinolíticos/farmacologia , Hemólise , Humanos , Hidrogéis/metabolismo , Metacrilatos/química , Adesividade Plaquetária/efeitos dos fármacos , Polimerização , Proteínas Citotóxicas Formadoras de Poros/farmacologia , Propriedades de Superfície
6.
BMJ Case Rep ; 14(8)2021 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-34344647

RESUMO

A 42-year-old diabetic man presented to the hospital with severe sepsis and multiorgan dysfunction. A probable respiratory source of sepsis was suspected because of suggestive clinical and radiological findings. He was critically ill and was therefore admitted to intensive care for further management including ventilatory support and renal replacement therapy. He was also found to have marked anaemia requiring multiple blood transfusions with clinical and laboratory evidence pointing towards severe haemolysis. Further workup for the aetiology of pneumonia established a diagnosis of Legionella by confirmatory tests namely legionella antigen in the urine and exponentially rising serum antibody titres. The cause for the severe haemolysis was found to be complement-mediated autoimmune haemolysis as determined by direct antiglobulin test positive for complement components C3 and negative for IgG. Such clinically significant autoimmune haemolysis as a presenting feature, rather than a late complication, has never before been reported in the literature.


Assuntos
Anemia Hemolítica Autoimune , Doença dos Legionários , Adulto , Anemia Hemolítica Autoimune/complicações , Anemia Hemolítica Autoimune/diagnóstico , Anemia Hemolítica Autoimune/terapia , Complemento C3 , Hemólise , Hospitalização , Humanos , Doença dos Legionários/complicações , Doença dos Legionários/diagnóstico , Masculino
7.
BMJ Case Rep ; 14(8)2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34417246

RESUMO

A 27-year-old woman presented with a history of excessive hair loss, loss of appetite, loss of weight, amenorrhoea and loss of axillary and pubic hair for 6 months followed by fever and vomiting for 5 months and abdominal pain for 1 month. During the course of her illness, the patient developed intravascular haemolysis as evidenced by a drop in haemoglobin, indirect hyperbilirubinaemia, raised lactate dehydrogenase (LDH) and haemoglobinuria. Examination revealed severe pallor, mild icterus, elevated jugular venous pressure, generalised lymphadenopathy and hyperpigmentation. Investigations revealed severe anaemia, indirect hyperbilirubinaemia, raised LDH and negative Coombs test. Antinuclear antibody and anti-dsDNA, anti-Sm and anti-SS-A/Ro antibodies were positive and complement C3 was low. The patient was diagnosed to have systemic lupus erythematosus and immune-mediated intravascular haemolysis and was treated with prednisolone and hydroxychloroquine. Haemolysis resolved following steroid therapy, and during follow-up, there were no further episodes of haemolysis.


Assuntos
Hemólise , Lúpus Eritematoso Sistêmico , Adulto , Teste de Coombs , Feminino , Humanos , Hidroxicloroquina/uso terapêutico , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Prednisolona/uso terapêutico
8.
BMC Genomics ; 22(1): 619, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34399690

RESUMO

BACKGROUND: Babesia rossi is a leading cause of morbidity and mortality among the canine population of sub-Saharan Africa, but pathogenesis remains poorly understood. Previous studies of B. rossi infection were derived from clinical cases, in which neither the onset of infection nor the infectious inoculum was known. Here, we performed controlled B. rossi inoculations in canines and evaluated disease progression through clinical tests and whole blood transcriptomic profiling. RESULTS: Two subjects were administered a low inoculum (104 parasites) while three received a high (108 parasites). Subjects were monitored for 8 consecutive days; anti-parasite treatment with diminazene aceturate was administered on day 4. Blood was drawn prior to inoculation as well as every experimental day for assessment of clinical parameters and transcriptomic profiles. The model recapitulated natural disease manifestations including anemia, acidosis, inflammation and behavioral changes. Rate of disease onset and clinical severity were proportional to the inoculum. To analyze the temporal dynamics of the transcriptomic host response, we sequenced mRNA extracted from whole blood drawn on days 0, 1, 3, 4, 6, and 8. Differential gene expression, hierarchical clustering, and pathway enrichment analyses identified genes and pathways involved in response to hemolysis, metabolic changes, and several arms of the immune response including innate immunity, adaptive immunity, and response to viral infection. CONCLUSIONS: This work comprehensively characterizes the clinical and transcriptomic progression of B. rossi infection in canines, thus establishing a large mammalian model of severe hemoprotozoal disease to facilitate the study of host-parasite biology and in which to test novel anti-disease therapeutics. The knowledge gained from the study of B. rossi in canines will not only improve our understanding of this emerging infectious disease threat in domestic dogs, but also provide insight into the pathobiology of human diseases caused by Babesia and Plasmodium species.


Assuntos
Babesia , Babesiose , Doenças do Cão , África ao Sul do Saara , Animais , Babesia/genética , Babesiose/tratamento farmacológico , Doenças do Cão/tratamento farmacológico , Doenças do Cão/genética , Cães , Hemólise
10.
Methods Mol Biol ; 2341: 25-30, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34264457

RESUMO

Many strains of Staphylococcus aureus produce a variety of cytolysins that target many different cell types to both fight the immune system and acquire nutrients. This includes hemolysins which destroy erythrocytes and are well studied virulence factors. Traditionally, hemolysin activity is measured on blood agar plates due to the simplicity of the assay. While this is telling, it cannot encapsulate the full story because S. aureus is known to behave differently in broth and on agar. Furthermore, plate-based assays are primarily semiquantitative and often a more accurate determination of hemolytic potential is needed to discern differences between strains. Here, we describe a method to quantify hemolysin activity from broth or similarly grown cells.


Assuntos
Eritrócitos/fisiologia , Proteínas Hemolisinas/análise , Staphylococcus aureus/crescimento & desenvolvimento , Animais , Proteínas de Bactérias/análise , Proteínas de Bactérias/metabolismo , Meios de Cultura/química , Proteínas Hemolisinas/metabolismo , Hemólise , Humanos , Staphylococcus aureus/metabolismo , Staphylococcus aureus/patogenicidade , Fatores de Virulência/análise , Fatores de Virulência/metabolismo
11.
BMJ Case Rep ; 14(7)2021 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-34253518

RESUMO

Jaundice is one of the most common situations during the neonatal period. Alloimmune haemolytic disease of the fetus and newborn (AHDFN) is a major cause of pathological jaundice during the neonatal period. Since the establishment of anti-D prophylaxis, other antigens have gained greater clinical importance. The maternal antierythrocyte antibody screen is of great importance in monitoring pregnancy and in predicting the risk of AHDFN. A positive result should alert to the possibility of AHDFN and promote close surveillance of fetal anaemia, as well as neonatal anaemia and hyperbilirubinaemia. We describe a case of AHDFN due to incompatibility of the Rhesus c (Rhc) subgroup, diagnosed in pregnancy, but without effective transmission of information in the perinatal period, so a positive maternal antierythrocyte antibody screen was missed. This case highlights the importance of non-RhD antigens in this disease, but also the importance of a successful handoff of information in the delivery room.


Assuntos
Eritroblastose Fetal , Doenças Fetais , Doenças Hematológicas , Eritroblastose Fetal/diagnóstico , Feminino , Feto , Hemólise , Humanos , Recém-Nascido , Gravidez
12.
Int J Mol Sci ; 22(13)2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34208826

RESUMO

PEGylation of antimicrobial peptides as a shielding tool that increases stability toward proteolytic degradation typically leads to concomitant loss of activity, whereas incorporation of ultrashort PEG-like amino acids (sPEGs) remains essentially unexplored. Here, modification of a peptide/ß-peptoid hybrid with sPEGs was examined with respect to influence on hydrophobicity, antibacterial activity and effect on viability of mammalian cells for a set of 18 oligomers. Intriguingly, the degree of sPEG modification did not significantly affect hydrophobicity as measured by retention in reverse-phase HPLC. Antibacterial activity against both wild-type and drug-resistant strains of Escherichia coli and Acinetobacter baumannii (both Gram-negative pathogens) was retained or slightly improved (MICs in the range 2-16 µg/mL equal to 0.7-5.2 µM). All compounds in the series exhibited less than 10% hemolysis at 400 µg/mL. While the number of sPEG moieties appeared not to be clearly correlated with hemolytic activity, a trend toward slightly increased hemolytic activity was observed for analogues displaying the longest sPEGs. In contrast, within a subseries the viability of HepG2 liver cells was least affected by analogues displaying the longer sPEGs (with IC50 values of ~1280 µg/mL) as compared to most other analogues and the parent peptidomimetic (IC50 values in the range 330-800 µg/mL).


Assuntos
Antibacterianos/síntese química , Peptidomiméticos/síntese química , Peptoides/síntese química , Polietilenoglicóis/química , Acinetobacter baumannii/efeitos dos fármacos , Antibacterianos/química , Antibacterianos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Farmacorresistência Bacteriana/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Hemólise , Células Hep G2 , Humanos , Interações Hidrofóbicas e Hidrofílicas , Testes de Sensibilidade Microbiana , Estrutura Molecular , Peptidomiméticos/química , Peptidomiméticos/farmacologia , Peptoides/química , Peptoides/farmacologia
13.
Hematology ; 26(1): 491-496, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34238137

RESUMO

Paroxysmal nocturnal hemoglobinuria (PNH) is a disease caused by a phosphatidylinositol glycan anchor biosynthesis class A (PIG-A) mutation in hematopoietic stem cells. There are three theories about the possible mechanism of the pathogenesis of PNH: immune escape, anti-apoptotic mechanism, and secondary gene mutation. There has been little gain in the knowledge regarding its pathogenesis during the last decade owing to the lack of representative cell lines and animal models. There have been recent reports about the successful creation of PNH mouse and PNH rhesus macaque models. The detection of glycosylphosphatidylinositol-anchor protein (GPI-AP)-deficient cells and/or fluorescently labeled variant of aerolysin (FLAER) test, estimation of erythrocyte life span, and hemolysis-related experiments demonstrated that these animal models of PNH had GPI-AP-deficient blood cells with shortened lifespans and increased sensitivity to complement-activated hemolysis. However, there were no clinical manifestations such as hemolysis and thrombosis in these animal models. This suggested that the PIG-A mutation is one of the several conditions required for PNH, but it alone is not enough to cause PNH.


Assuntos
Modelos Animais de Doenças , Hemoglobinúria Paroxística/patologia , Animais , Técnicas de Inativação de Genes , Hemoglobinúria Paroxística/genética , Hemólise , Humanos , Macaca mulatta , Proteínas de Membrana/genética , Camundongos , Mutação
14.
J Extra Corpor Technol ; 53(2): 125-129, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34194078

RESUMO

Hemolysis is a common complication associated with mortality on extracorporeal membrane oxygenation (ECMO). Plasma-free hemoglobin (PFH) is the most commonly used biomarker reported for hemolysis on ECMO. This test is not readily available at all institutions, and other more readily available tests may indicate hemolysis nearly as well or as well as PFH. The purpose of this study was to study the correlation of other biomarkers of hemolysis to PFH on ECMO. All patients younger than 21 years placed on ECMO in a quaternary children's hospital between January 2013 and December 2016 were included in the study; biomarkers (urine hemoglobin [U-Hb], PFH, lactate dehydrogenase [LDH], aspartate aminotransferase [AST], gross hemolysis, and red cell distribution width (RDW)) were collected from the medical record. Descriptive statistics and repeated bivariate analyses were determined using SPSS 22.0. The median age on day 0 of ECMO was 29 days (.08 years) (IQR: 2; 319 days (.005; .875 years)). The median weight was 3.9 kg (IQR: 2.8; 8.6), and the median total duration of the ECMO run was 10.48 days (IQR: 4.25; 14), with 82% of all the patients being on venoarterial ECMO. There was no correlation between hematuria on urinalysis and the level of PFH (p = .338). There was a statistically significant positive correlation between PFH and the following respective biomarkers: gross hemolysis on the routine chemistry studies (p < .01, Rho = .439), AST (p < .01, Rho = .439), RDW (p < .01, Rho = .190), LDH (p < .01, Rho = .584), and AST (when associated elevated alanine transaminase (ALT) levels were censored) (p < .01, Rho = .552). U-Hb correlated poorly with PFH. The serum biomarkers AST (in the absence of ALT elevation) and LDH can be useful surrogates for PFH to quantify hemolysis on ECMO in pediatric patients.


Assuntos
Oxigenação por Membrana Extracorpórea , Biomarcadores , Criança , Oxigenação por Membrana Extracorpórea/efeitos adversos , Hemólise , Humanos , Estudos Retrospectivos
15.
Nephrol Nurs J ; 48(3): 237-240, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34286933

RESUMO

Hemolysis may be an infrequent cause of hemodialysis blood leak alarms. We report the case of an unresponsive adult male who was placed on hemodialysis with a high-flux dialyzer. Within five minutes, the blood leak alarm sounded. The care team discontinued treatment and made two additional attempts to reinitiate hemodialysis with different machines, blood tubing lots, and brands of high-flux dialyzers, but continued to receive blood leak alarms. Laboratory studies were consistent with severe hemolysis. The attending nephrologist subsequently ordered continuous veno-venous hemofiltration, which was initiated and continued into the following day without incident or alarm. The patient later expired from complications of near-drowning. In the event of significant hemolysis, continuous kidney replacement therapy or hemodialysis with a low-flux dialyzer, and a lower ultrafiltration rate may be indicated.


Assuntos
Hemólise , Afogamento Iminente , Adulto , Água Doce , Humanos , Masculino , Diálise Renal/efeitos adversos
16.
Clin Lab ; 67(7)2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34258964

RESUMO

BACKGROUND: The effectiveness of aspiration and vacuum filling method with an adaptor in reducing hemolysis was investigated. METHODS: The study was conducted in the yellow zone of the Emergency department. Two different apparatuses that draw blood with two different techniques from an IV catheter were compared with our routine procedure. The first system drew blood with aspiration technique into 4.9 mL serum gel tube (Sarstedt S-Monovette®). The second was vacuum filling with a specific adaptor attached to the same catheter drawing the blood into vacuumed serum separator tubes (BD Vacutainer® SST™II and Luer-Lok™ Access Device (LLAD). In our routine, we use plastic syringes and deliver it into the same serum separator vacuum tubes. We measured the hemolysis index, AST, CK, potassium, and LDH. RESULTS: Hemolysis rates of aspiration method vs. routine were 0.80% and 38.7% (p < 0.001) and of vacuum filling with adaptor vs. routine were 13.5% and 40.6%, respectively (p = 0.0001). The hemolysis rate of the aspiration method was lower than the vacuum filling adaptor method (p = 0.0004). Both techniques showed better performance when measured parameters were compared; aspiration technique being the superior (all p < 0.0001). CONCLUSIONS: Aspiration method was more successful then vacuum filling methods in reducing hemolysis.


Assuntos
Coleta de Amostras Sanguíneas , Hemólise , Cateteres , Serviço Hospitalar de Emergência , Testes Hematológicos , Humanos
17.
Anal Methods ; 13(30): 3410-3413, 2021 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-34254068

RESUMO

BACKGROUND: To investigate the effect of hemolysis on serum procalcitonin (PCT) detected by electrochemiluminescence (ECL) and to explore the possibility of establishment of a correction equation. METHODS: Fifty-one blood samples from 17 patients were collected. Hemolytic samples, of which the final concentrations of hemoglobin (Hb) were 5, 10, 15 and 20 g L-1, were prepared by adding lysed homologous RBCs to serum, and then the PCT levels were detected and compared. RESULTS: with the increasing degree of sample hemolysis, PCT bias elevated from -13.12% to -38.86% as the hemolysis degree increased from 5 g L-1 to 20 g L-1, respectively. There was a linear correlation of PCT levels between the original and hemolytic samples with the same hemolytic degree (r > 0.97). Using the correction equation log10PCTcorr = 0.962(log10PCThemo) +0.251(log10Hb) - 0.126, the corrected PCT values from the hemolytic samples showed acceptable consistency with the original values (p > 0.05). CONCLUSIONS: Hemolysis has a negative interference on PCT values assayed by ECL. The serum PCT level is correlated negatively with the Hb level in the blood sample. The established correction equation could reduce inappropriate antibiotics application and improve the experience of patients in the emergency department.


Assuntos
Hemólise , Pró-Calcitonina , Serviço Hospitalar de Emergência , Eritrócitos , Humanos , Soro
18.
J Phys Chem B ; 125(30): 8450-8459, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34254509

RESUMO

Melittin, a hemolytic peptide present in bee venom, represents one of the most well-studied amphipathic antimicrobial peptides, particularly in terms of its membrane interaction and activity. Nevertheless, no consensus exists on the oligomeric state of membrane-bound melittin. We previously reported on the differential microenvironments experienced by melittin in zwitterionic and negatively charged phospholipid membranes. In this work, we explore the role of negatively charged lipids in the oligomerization of membrane-bound melittin (labeled with 7-nitrobenz-2-oxa-1,3-diazol-4-yl (NBD)) utilizing a quantitative photobleaching homo-FRET assay. Our results show that the presence of negatively charged lipids decreases melittin oligomeric size to ∼50% of that observed in zwitterionic membranes. This is possibly due to differential energetics of binding of the peptide monomer to membranes of different compositions and could explain the reduced lytic activity yet tighter binding of melittin in negatively charged membranes. These results constitute one of the first experimental observations on the role of phospholipid headgroup charge in the oligomerization of melittin in membranes and is relevant in light of previous apparently contradictory reports on oligomerization of membrane-bound melittin. Our results highlight the synergistic interplay of peptide-membrane binding events and peptide oligomerization in modulating the organization, dynamics, and function of amphipathic α-helical peptides.


Assuntos
Bicamadas Lipídicas , Meliteno , Hemólise , Humanos , Membranas , Fosfolipídeos
19.
Transfusion ; 61 Suppl 1: S22-S31, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34269432

RESUMO

BACKGROUND: Civilian and military guidelines recommend early balanced transfusion to patients with life-threatening bleeding. Low titer group O whole blood was introduced as the primary blood product for resuscitation of massive hemorrhage at Haukeland University Hospital, Bergen, Norway, in December 2017. In this report, we describe the whole blood program and present results from the first years of routine use. STUDY DESIGN AND METHODS: Patients who received whole blood from December 2017 to April 2020 were included in our quality registry for massive transfusions. Post-transfusion blood samples were collected to analyze isohemagglutinin (anti-A/-B) and hemolysis markers. Administration of other blood products, transfusion reactions, and patient survival (days 1 and 30) were recorded. User experiences were surveyed for both clinical and laboratory staff. RESULTS: Two hundred and five patients (64% male and 36% female) received 836 units in 226 transfusion episodes. Patients received a mean of 3.7 units (range 1-35) in each transfusion episode. The main indications for transfusion were trauma (26%), gastrointestinal (22%), cardiothoracic/vascular (18%), surgical (18%), obstetric (11%), and medical (5%) bleeding. There was no difference in survival between patients with blood type O when compared with non-group O. Haptoglobin level was lower in the transfusion episodes for non-O group patients, however no clinical hemolysis was reported. No patients had conclusive transfusion-associated adverse events. Both clinical and laboratory staff preferred whole blood to component therapy for massive transfusion. DISCUSSION: The experience from Haukeland University Hospital indicates that whole blood is feasible, safe, and effective for in-hospital treatment of bleeding.


Assuntos
Transfusão de Sangue , Ressuscitação , Reação Transfusional/etiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Transfusão de Sangue/métodos , Criança , Pré-Escolar , Feminino , Hemólise , Hospitais , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Noruega/epidemiologia , Ressuscitação/métodos , Reação Transfusional/sangue , Reação Transfusional/patologia , Adulto Jovem
20.
Transfusion ; 61 Suppl 1: S8-S14, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34269441

RESUMO

BACKGROUND: Low-titer Group O Whole Blood (LTOWB) is used with increasing frequency in adult and pediatric trauma and massive bleeding transfusion protocols. There is a risk of acute hemolytic reactions in non-group O recipients due to the passive transfusion of anti-A and anti-B in the LTOWB. This study investigated the hemolysis risk among pediatric recipients of LTOWB. STUDY DESIGN AND METHODS: Blood bank records were queried for pediatric recipients of LTOWB between June 2016 and August 2020 and merged with clinical data. The primary outcome was laboratory evidence of hemolysis as manifested by changes in lactate dehydrogenase (LDH), haptoglobin, total bilirubin, reticulocyte count, potassium, and creatinine. Per protocol, these values were collected on hospital days 0-2 for recipients of LTOWB. Transfusion reactions were reported to the hospital's blood bank. RESULTS: Forty-seven children received LTOWB transfusion between 2016 and 2020; 21 were group O and 26 were non-group O. The groups were comparable in terms of the total volume of transfused blood products, demographics, and clinical outcomes. The most common indication for LTOWB transfusion was hemorrhagic shock due to trauma. There were no clinically or statistically significant differences in baseline, post-transfusion day 1, or post-transfusion day 2 hemolysis markers between the group O and non-group O LTOWB recipients. There were no adverse events or transfusion reactions reported. DISCUSSION: Use of up to 40 ml/kg of LTOWB appears to be serologically safe for children in hemorrhagic shock.


Assuntos
Sistema ABO de Grupos Sanguíneos/sangue , Transfusão de Sangue , Hemólise , Reação Transfusional/sangue , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Reação Transfusional/patologia
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