Free Bilirubin Research Articles

Characterization and Clinical Significance of Hemolysis After Pulsed Field Ablation for Atrial Fibrillation: Results of a Multicenter Analysis.

Pulsed field ablation (PFA) is increasingly used in clinical practice for the treatment of atrial fibrillation. While the susceptibility of erythrocytes to electroporation is well established, the effect of cardiac PFA technologies on hemolysis has remained underreported. The aim of this study was to investigate the incidence, severity, and clinical impact of PFA-induced hemolysis. We included n=145 patients undergoing atrial fibrillation catheter ablation with a pentaspline PFA catheter (biphasic, bipolar pulses of 2 kV) and n=70 patients receiving radiofrequency ablation (40-90 W) at 4 high-volume European centers. The lesion set comprised pulmonary vein isolation for paroxysmal atrial fibrillation and pulmonary vein isolation±additional lesions for persistent atrial fibrillation. Hemolysis and renal function biomarkers were analyzed in blood samples at baseline, at the end of ablation, and 24 hours after the procedure. Baseline characteristics were well balanced between groups (overall mean, 65.7±9.4 years; 69.3% male). The ablation procedures comprised a mean of 61.6±27.4 PFA deliveries and 26.3±15.0 minute RF duration. Hemolysis was detected in 94.3% versus 6.8% of patients after PFA versus radiofrequency ablation (P<0.001): PFA was associated with significantly lower haptoglobin levels (0.5±0.4 versus 1.0±0.4 g/L), while free plasma hemoglobin (592.8±330.6 versus 147.8±183.0 mg/L), bilirubin (21.3±11.3 versus 14.8±8.8 µmol/L), and LDH (lactate dehydrogenase, 352.7±115.7 versus 253.2±56.5 U/L) were significantly higher after PFA versus radiofrequency ablation (all P<0.001). Hemolysis correlated with the number of PFA deliveries (r=0.62 [95% CI, 0.33-0.80]; P<0.001), with the highest severity occurring ≥54 PFA deliveries. After PFA, hemoglobinuria occurred in 36.4%, while creatinine increase was higher in patients with baseline glomerular filtration rate <50 mL/min versus baseline glomerular filtration rate >50 mL/min (Δcrea, 27.0±103.1 versus -0.2±12.1 µmol/L; P=0.010). Intravascular hemolysis is a frequent finding after PFA and increases with the number of PFA deliveries. Until the clinical impact of PFA-associated hemolysis is fully elucidated, a careful titration of PFA deliveries during the ablation procedure is warranted.

Fabrication and characterization of chitin/collagen aerogels crosslinked by KH560 for bilirubin adsorption

Hemoperfusion is regarded as the most effective treatment for hyperbilirubinemia. The adsorbent play crucial important role for bilirubin removal. An ideal adsorbent should possess good biocompatibility as well as high bilirubin adsorption capacity. In this study, two natural polymers composed of chitin and collagen plus KH560 that served as a crosslinking agent were selected to fabricate chitin/collagen composite aerogels (CKC), and potentially used as efficient bilirubin adsorption. The fabricated CKC aerogels exhibited homogeneous, dense and nanoscale 3D-porous nanofibrous structures. And the CKC aerogels showed high adsorption capacity (209.62 ± 2.28 mg/g) for free bilirubin within 4 h. More important, dynamic adsorption experiment illustrated the adsorption capacity reached to 265.22 ± 4.77 mg/g, larger than that of static adsorption. The further tests manifested the CKC aerogels had excellent blood compatibility and no toxicity in vivo. This novel naturally-based aerogels were an economical, biocompatible and efficient adsorbent for the bilirubin removal, potentially providing new ideas for development of new adsorbents.

Ultra-low level detection of biomarker bilirubin by graphene quantum dots and bovine serum albumin enabled turn-on sensing

It is known that concentration of unbound (free) bilirubin (BR) instead of the total bilirubin is the critical determinant of cellular uptake and toxicity of bilirubin. Thus, developing fast, effective and sensitive technique for detecting BR, a unique and important biomarker of liver dysfunction, has a long-standing demand. In this study, attempts were made to explore if biocompatible graphene quantum dots (GQDs) could be employed to probe BR at an ultra-low level in aqueous environment through optical techniques. Thus, understanding the possible interactions involved between GQDs and BR is important and necessary to develop protocol for probing BR. The detailed spectral analysis shows that BR molecule quenches the fluorescence of GQDs which may be attributed to a possible fluorescence resonance energy transfer (FRET) involved between the excited state of GQDs and BR. The micro-calorimetric and circular dichroic (CD) measurements have provided binding and structural information in the process of interactions. It is established that with the help of synthesized GQDs, BR can be detected as low as 0.15 nM selectively and this appears to be the most sensitive amongst other available methods. Interestingly, it is observed that the addition of bovine serum albumin (BSA) facilitates the recovery of the BR-induced loss in fluorescence intensity of GQDs. The adopted strategy demonstrates that GQD may act as a sensitive fluorescent “turn off–on” probe for detection of BR. The proposed optical method based protocol validated with serum samples isolated from blood for rapid detection of BR at ultra-low level may help in developing a suitable sensing device in future.

Theory-Driven Tailoring of the Microenvironment of Quaternary Ammonium Binding Sites on Electrospun Nanofibers for Efficient Bilirubin Removal in Hemoperfusion.

Efficient adsorbents for excess bilirubin removal are extremely important for the treatment of hyperbilirubinemia. However, traditional adsorbents, such as activated carbons and ion-exchange resins, still suffer from dissatisfactory adsorption performance and poor blood compatibility. Herein, we adopted a rational design strategy guided by density functional theory (DFT) calculations to prepare blood-compatible quaternary ammonium group grafted electrospun polyacrylonitrile nanofiber adsorbents. The calculation analysis and adsorption experiments were used to investigate the structure-function relationship between group types and bilirubin adsorption, both indicating that quaternary ammonium groups with suitable configurations played a crucial role in bilirubin binding. The obtained nanofiber adsorbents showed the bilirubin removal efficiency above 90% even at a coexisting BSA concentration of 50 g L-1. The maximum adsorption capacities were 818.9 mg g-1 in free bilirubin solution and 163.7 mg g-1 in albumin bound bilirubin solution. The nanofiber adsorbents also showed considerable bilirubin removal in dynamic adsorption to reduce the bilirubin concentration to a normal level, which was better than commercial activated carbons. Our study demonstrates the high feasibility of a theory-driven design method for the development of grafted electrospun nanofibers, which have good potential as bilirubin adsorbents in hemoperfusion applications.

Impaired excitability of nucleus tractus solitarius neurons in a neonatal rat model of hyperbilirubinemia

Hyperbilirubinemia is associated with multiple morbidities including apnea of prematurity in preterm infants. Bilirubin, a byproduct of hemoglobin breakdown, is not excreted normally and results in high circulating levels giving rise to a state of hyperbilirubinemia. Free bilirubin (not bound to albumin) can cross the blood-brain barrier and be neurotoxic. Prior studies have shown that a systemic injection of bilirubin accumulates in the brainstem and is associated with an impaired ventilatory response to hypercapnia and an augmented hypoxic ventilatory depression. Here, using the Gunn rat model of endogenous hyperbilirubinemia, we investigated its effects on the excitability of neurons of the nucleus tractus solitarius (NTS). The homozygous Gunn rat (jj) model of hyperbilirubinemia lacks uridine diphosphate-glucuronosyltransferase-1A1, an enzyme which is needed to catabolize bilirubin. Heterozygous Nj Gunn rat pups were used for control. On postnatal (P) day 5, Nj and jj rat pups received either a 200mg/kg intraperitoneal injection of sulfadimethoxine (SDMX), which dissociates bilirubin from albumin resulting in increased levels of circulating free bilirubin, or an equivalent amount of saline as a vehicle control. Whole cell patch clamp was performed on NTS neurons two days later (P7) to assess characteristics of evoked excitatory postsynaptic currents (eEPSC).The amplitude of the evoked stimulus response to a 20Hz stimulus train was significantly increased in NTS neurons from jj+saline pups when compared to cells from Nj+saline and Nj+SDMX animals (p&lt;0.05). This increased amplitude was no longer present after SDMX treatment of jj pups. Additionally, jj+saline NTS neurons did not exhibit any failure to solitary tract stimulation, whereas SDMX treatment significantly increased the failure rate during a 20Hz stimulus train (jj+saline =0.0%±0.0, jj+SDMX= 18.63%±8.82, p&lt;0.05). Comparison of failure rate of jj+saline to Nj+saline (6.63%±3.12, p&lt;0.05) was also statistically significant. The hyper-responsive NTS neurons of jj+saline rats may be an adaptive response to the deleterious effects of circulating (bound and unbound) bilirubin. However, the impaired response of neurons in jj+SDMX rats may reflect neurotoxic effects of increased free bilirubin leading to impaired neurotransmission. The latter is consistent with the high failure rate of NTS neurons in jj+SDMX rats. These data may have implications for impaired respiratory control mechanisms involved in mediating essential vagally mediated ventilatory defense responses to hypoxemia and may contribute to the apnea of prematurity associated with hyperbilirubinemia in preterm infants. William and Lois Briggs Endowment. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Photo-crosslinked hydrogel as a sensing platform for sensitive detection of free bilirubin in urine samples

In cases of liver lesions or metabolic blockages, the accumulation of bilirubin in the blood can lead to hyperbilirubinemia, resulting in jaundice. Hence, the development of a rapid and highly selective assay strategy for accurately quantifying free bilirubin concentrations in humans is crucial for clinical diagnosis and treatment. In this study, a postsynthetic modification (PSM) strategy was used to obtain UiO-66-PSM (UP) by the aldimine condensation reaction of metal-organic framework UiO-66-NH2 with 2,3,4-trihydroxybenzaldehyde. UP itself possesses strong fluorescent properties. Subsequently, UiO-66-PSM-Fe (UPF) was synthesized by incorporating Fe3+ onto the UP surface using a one-pot method, where the interaction of Fe3+ with UP induced fluorescence quenching. Bilirubin has a strong binding affinity for Fe3+. Therefore, it can react with the UPF, losing Fe3+ and regaining fluorescence, and thus realizing the detection of bilirubin. In order to further improve the detection outcome and facilitate the application, UPF was loaded onto gelatin methacryloyl hydrogel to construct a fluorescence sensor. This enabled highly sensitive determination of bilirubin with a method limit of detection of 5.67 pM. Furthermore, genuine human urine samples were analyzed, demonstrating the practical application of the assay in discovering human health conditions associated with bilirubin.

Turn-Off Fluorometric Determination of Bilirubin Using Facile Synthesized Nitrogen-Doped Carbon Dots as a Fluorescent Probe.

Bilirubin plays a significant role in human health management, particularly in the case of jaundice. Because of the need for the monitoring of bilirubin levels in jaundice patients, the development of a robust sensitive method becomes essential. Here, we describe the development ofa highly sensitive and selective turn-off fluorometric detectionmethod for bilirubin in blood serum samples using nitrogen-doped carbon dots (N-CDs). N-CDs was synthesized by the pyrolysis process, using citric acid and L-asparagine as the carbon and nitrogen sources, respectively. The prepared N-CDs solution showed highly intense blue emission with good stability. The HR-TEM image of N-CDs revealed spherical dot-like structures with anaverage size calculated to be 7.16nm. Further, the surface functional groups of N-CDs were analyzed by FT-IR, Raman, XRD, and XPS techniques. Fluorescence spectra showed the maximum emission intensity at 443nm (λex). The linear range of addition was performed from 1 to 150µM, and the limit of detection (LOD) was determined to be 1.97nM. The emission of N-CDs was quenched by Förster Resonance Energy Transfer (FRET) by adding bilirubin. These N-CDs showed extraordinary sensitivity and selectivity in the detection of bilirubin. Hence, this fluorescent probe has been proven successful in detecting the concentration of free bilirubin in human serum samples.

Collagen-modified chitosan microsphere as a novel hemoperfusion adsorbent for efficient removal of bilirubin from human plasma

Hemoperfusion is one of the most effective treatments for the removal of bilirubin from the blood. Chitosan (CS) has been widely investigated as a hemoperfusion adsorbent to remove bilirubin due to its biocompatibility and biodegradability. However, the limited adsorption capacity of CS for free bilirubin or albumin-rich bilirubin solution, and the strong adsorption for albumin, limit its extensive use. The goal of this work is to improve specific bilirubin adsorption of CS while reducing its adsorption for albumin. In this study, collagen (Col) was chosen as a ligand and grafted onto the surface of CS microspheres to form CS-Col microspheres and therefore to improve their adsorption performance for bilirubin. The maximum adsorption capacity of the CS-Col microspheres for bilirubin increases from 24.2 to 76.9 mg/g. The enhancement factor is higher than that of other CS-based adsorbents. Moreover, the adsorption of CS-Col microspheres for albumin is effectively reduced to 2.6 %, while maintaining good blood compatibility. Compared to other CS-based bilirubin adsorbents, our CS-Col microspheres have the advantage of specific adsorbing bilirubin against albumin due to introducing collagen. This work provides new directions for designing high-performance bilirubin adsorbents. Our CS-Col microspheres show great promise for the treatment of hyperbilirubinemia.

Simultaneous determination of free biliverdin and free bilirubin in serum: A comprehensive LC-MS approach

BackgroundPrognosis, diagnosis, and treatment of several diseases strongly rely on the sensitive, selective, and accurate determination of specific biomarkers in relevant biological samples. Free biliverdin and free bilirubin represent important new biomarkers of oxidative stress, however, the lack of suitable analytical methods for their determination has hindered progress in biomedical and clinical research. ResultsHere, we introduce a first comprehensive approach for robust and simultaneous determination of these bilins in serum using liquid chromatography – mass spectrometry (LC-MS). The developed analytical method exhibits linearity for both analytes within the concentration range of 0.5–100 nM, with limits of detection and quantitation determined at 0.1 nM and 0.5 nM, respectively. Moreover, several analytical pitfalls related to the intrinsic molecular structures of free bilirubin and free biliverdin and their trace concentration levels in biological samples are discussed here in detail for the first time. We have shown that the solubility, chemical stability, and affinity of these bilins to various materials strongly depend on the solvent, pH, and addition of stabilizing and chelating agents. Finally, the validated LC-MS method was successfully applied to the analysis of both bilins in fetus bovine serums, yielding higher free bilirubin/biliverdin ratios compared with previously reported values for human serum. SignificanceFailure to recognize and address the challenges presented here often leads to substantial analytical errors and consequently biased interpretation of the obtained results. This pertains not only to LC-MS, but also to many other analytical platforms due to the compound-derived sources of error.

B-320 Development of Two-step Sandwich CLEIA Kit for Tacrolimus With Automated Sample-Pretreatment Process, LUMIPULSE Presto® iTACT® Tacrolimus

Abstract Background Tacrolimus (The other name: FK506) is an immunosuppressive drug used for preventing rejection of allotransplantation and treating atopic dermatitis or rheumatoid arthritis. The complex consisting of Tacrolimus and FK506 binding protein binds to calcineurin and suppresses expression of Interleukin-2 (IL-2) and IL-2 induced immune response. Although tacrolimus is a useful immunosuppressive drug, this medicine causes serious side effects, such as renal dysfunction, opportunistic infections due to the excessive immunosuppression, and so on. Therefore, the measurement of the tacrolimus concentration in blood is required to obtain the maximum tacrolimus therapeutic effect without side effects. It is known that 95 percent of tacrolimus in blood localizes in the inside of erythrocyte, and this localization imposes cumbersome pretreatment process of whole blood. Almost all diagnostic reagents for tacrolimus need the manual whole blood pretreatment process that defaces the reliability of measurement values. And the existing diagnostic reagents often show the high cross-reactivity against the metabolite products of tacrolimus. To solve these inconveniences, we developed a highly-specific chemiluminescence enzyme immunoassay (CLEIA) for tacrolimus using a new automated sample-pretreatment process on a fully automated LUMIPULSE® L2400 analyzer. In this study, we report the basic performance of this new tacrolimus assay named as LUMIPULSE Presto® iTACT® Tacrolimus. Methods LUMIPULSE Presto® iTACT® Tacrolimus is the two-step sandwich CLEIA with the on-board sample-pretreatment process. All evaluations were executed on LUMIPULSE® L2400 analyzer (FUJIREBIO INC.). The on-board sample-pretreatment process is performed simultaneously with the first immune-reaction in sandwich CLEIA, and the total reaction time is 20 min. Limit of detection (LoD) and Limit of quantification (LoQ), within-run precision, day-to-day reproducibility, linearity, endogenous interferences, anticoagulative interferences, tacrolimus metabolites interferences and the correlation with current tacrolimus assay were evaluated in LUMIPULSE Presto® iTACT® Tacrolimus. Results Both of LoD and LoQ of LUMIPULSE Presto® iTACT® Tacrolimus were 0.12 ng/mL. Within-run precisions (% CVs) using three control samples were 0.4%–2.5%. Day-to-day reproducibility in five days were 0.4%–1.9%. We determined the linearity ranged from 0.29 to 48.80 ng/mL. Up to 19.7 mg/dL of conjugated bilirubin, 18.8 mg/dL of free bilirubin, 1620 FTU of chyle, 2000 mg/dL of triglycerides, 1000 IU/mL of RF, and 1010 ng/mL of HAMA, and 4–12 g/dL of proteins including albumin did not affect tacrolimus measurements. In addition, there was no influence by EDTA 2K and EDTA 2Na up to 10 mg/mL. The cross-reactivities of four tacrolimus metabolites (M-I, M-II, M-III, and M-IV) were respectively 0.4%–1.0%, 0.0%–0.8%, -0.7%–0.2%, and 0.7%–1.6%. Comparing to the existing chemiluminescence immunoassay (CLIA) with 128 specimens, the correlation coefficient was 1.0, and the slope calculated by Passing-Bablok method is 1.04. Comparing to the existing electrochemiluminescence immunoassay (ECLIA) with 137 specimens, the correlation coefficient was 1.0, and the slope calculated by Passing-Bablok method is 1.07. Conclusion The fundamental performance of LUMIPULSE Presto® iTACT® Tacrolimus is satisfactory and the on-board sample-pretreatment process of this assay is expected to contribute to reducing the burden and inconvenience of laboratory personnel.

Free Bilirubin Induces Neuro-Inflammation in an Induced Pluripotent Stem Cell-Derived Cortical Organoid Model of Crigler-Najjar Syndrome.

Bilirubin-induced neurological damage (BIND), which might progress to kernicterus, occurs as a consequence of defects in the bilirubin conjugation machinery, thus enabling albumin-unbound free bilirubin (BF) to cross the blood-brain barrier and accumulate within. A defect in the UGT1A1 enzyme-encoding gene, which is directly responsible for bilirubin conjugation, can cause Crigler-Najjar syndrome (CNS) and Gilbert's syndrome. We used human-induced pluripotent stem cell (hiPSC)-derived 3D brain organoids to model BIND in vitro and unveil the molecular basis of the detrimental effects of BF in the developing human brain. Healthy and patient-derived iPSCs were differentiated into day-20 brain organoids, and then stimulated with 200 nM BF. Analyses at 24 and 72 h post-treatment point to BF-induced neuro-inflammation in both cell lines. Transcriptome, associated KEGG, and Gene Ontology analyses unveiled the activation of distinct inflammatory pathways, such as cytokine-cytokine receptor interaction, MAPK signaling, and NFκB activation. Furthermore, the mRNA expression and secretome analysis confirmed an upregulation of pro-inflammatory cytokines such as IL-6 and IL-8 upon BF stimulation. This novel study has provided insights into how a human iPSC-derived 3D brain organoid model can serve as a prospective platform for studying the etiology of BIND kernicterus.

Dietary Zinc Status in Offspring of Pregnant Rats Fed on a Zinc-Deficient Diet Is Associated with Serum Albumin, Ast, and Alt Levels

Objective: This study was carried out to investigate whether dietary zinc status is associated with serum albumin, AST and ALT levels in male offspring of mother rats fed a zinc deficient diet. Methods: The study was carried out on male offspring (Groups 1, 2, 3) born to rats fed a zinc deficient diet and on male offspring (Group 4) born to mothers fed a standard diet. Group 1: Zinc deficient, Group 2; standard rat chow, Group 3: Zinc supplemented diet. Animals of group 4 were used as control group. After the completion of the experimental stages of the study, albumin, AST, ALT, free and total bilirubin levels in serum samples taken from animals were determined by spectrophotometric method. Results: Dietary zinc deficiency (group 1) significantly decreased serum albumin values (p&lt;0.004). Animals in both the zinc deficient (Group 1) group and the Group 2 animals born to mothers fed a zinc deficient diet and fed standard rat chow had the highest AST and ALT levels (p&lt;0.001). Conclusion: The present study is the first to show that dietary zinc status can directly affect liver function in rats born to zinc deficient mothers by causing changes in serum albumin, AST and ALT levels.

Bilirubin Concentration in Follicular Fluid Is Increased in Infertile Females, Correlates with Decreased Antioxidant Levels and Increased Nitric Oxide Metabolites, and Negatively Affects Outcome Measures of In Vitro Fertilization.

In a previous study, we showed that various low-molecular-weight compounds in follicular fluid (FF) samples of control fertile females (CFF) have different concentrations compared to those found in FF of infertile females (IF), before and after their categorization into different subgroups, according to their clinical diagnosis of infertility. Using the same FF samples of this previous study, we here analyzed the FF concentrations of free and bound bilirubin and compared the results obtained in CFF, IF and the different subgroups of IF (endometriosis, EM, polycystic ovary syndrome, PCOS, age-related reduced ovarian reserve, AR-ROR, reduced ovarian reserve, ROR, genetic infertility, GI and unexplained infertility, UI). The results clearly indicated that CFF had lower values of free, bound and total bilirubin compared to the respective values measured in pooled IF. These differences were observed even when IF were categorized into EM, PCOS, AR-ROR, ROR, GI and UI, with EM and PCOS showing the highest values of free, bound and total bilirubin among the six subgroups. Using previous results of ascorbic acid, GSH and nitrite + nitrate measured in the same FF samples of the same FF donors, we found that total bilirubin in FF increased as a function of decreased values of ascorbic acid and GSH, and increased concentrations of nitrite + nitrate. The values of total bilirubin negatively correlated with the clinical parameters of fertilization procedures (number of retrieved oocytes, mature oocytes, fertilized oocytes, blastocysts, high-quality blastocysts) and with clinical pregnancies and birth rates. Bilirubin concentrations in FF were not linked to those found in serum samples of FF donors, thereby strongly suggesting that its over production was due to higher activity of heme oxygenase-1 (HO-1), the key enzyme responsible for bilirubin formation, in granulosa cells, or cumulus cells or oocytes of IF and ultimately leading to bilirubin accumulation in FF. Since increased activity of HO-1 is one of the main enzymatic intracellular mechanisms of defense towards external insults (oxidative/nitrosative stress, inflammation), and since we found correlations among bilirubin and oxidative/nitrosative stress in these FF samples, it may reasonably be supposed that bilirubin increase in FF of IF is the result of protracted exposures to the aforementioned insults evidently playing relevant roles in female infertility.

Implementation of neonatal phototherapy with the BiliCocoon Bag® device in the maternity ward and impact on mother–infant separation

BackgroundFree bilirubin jaundice is a frequent pathology in the neonatal period. The major complication is neurological toxicity, the most severe form of which is kernicterus. Overall, 5%–10% of jaundiced neonates require treatment. The first-line treatment is phototherapy, with intensive phototherapy being the gold standard. Other equipment is also available, including the BiliCocoon Bag®. It is a safe and controlled therapy that can be performed in the mother's room in the maternity ward, thereby avoiding separation and allowing for breast- or bottle-feeding during treatment. It is easy to install and does not require protective glasses, thus no scope or hospitalization. In our maternity ward, all neonates requiring intensive phototherapy are hospitalized in the neonatology ward. ObjectiveThe objective of our study was to evaluate the number of avoided hospitalizations in neonatology for free bilirubin jaundice since the introduction, according to a strict protocol, of the BiliCocoon Bag® device. Material and MethodThis was a single-center retrospective cohort study using data of newborns usually collected as part of standard care. Children born in our maternity ward during an 18-month period (August 1, 2020 to January 31, 2022) were included. Causes of jaundice, age at the beginning and mode of treatment, number of sessions for each device, and length of stay were compared. Results are presented as number and percentage with median (25th–75th) or mean (extremes) values for categorical and continuous variables, respectively. A t-test was used to compare the means of the independent groups. ResultsA total of 316 newborns were included. Physiological jaundice was the main cause of jaundice. The median age for the first phototherapy treatment was 54.5 h (30–68). The 316 neonates needed 438 phototherapy sessions: 235 (74%) neonates required only one phototherapy session, 85 (36%) of them were treated with the BiliCocoon Bag®. For the 81 children who needed two or more phototherapy sessions, 19 children (23.5%) were treated by tunnel phototherapy and then the BiliCocoon Bag®, and eight children (10%) by BiliCocoon Bag® alone. The BiliCocoon Bag® enabled a relative reduction in the hospitalization rate of 38% and avoided hospitalization for approximately one third of the newborns treated. The BiliCocoon Bag® failure rate was 3.6% and the average length of stay was comparable between the two types of treatment. ConclusionFollowing a strict protocol of use, the BiliCocoon Bag® is a reliable method and a good alternative to intensive phototherapy for newborns in the maternity ward, as it avoids hospitalization and mother–infant separation.

Impact of Protein Binding Capacity and Daily Dosage of a Drug on Total Serum Bilirubin Levels in Susceptible Infants.

Hyperbilirubinemia is a common pathological condition in neonates. Free bilirubin can penetrate the blood-brain barrier (BBB), which can lead to bilirubin neurotoxicity. In the context of predicting the risk of bilirubin neurotoxicity, although the specificity and sensitivity of free bilirubin levels are higher than those of total serum bilirubin (TSB), free bilirubin is not widely monitored in clinical practice. The threshold TSB levels at which phototherapy must be administered have been established previously. However, TSB levels are not well correlated with neurodevelopmental outcomes. Currently, TSB levels are commonly used to guide phototherapy for neonatal hyperbilirubinemia. Some clinical drugs can displace bilirubin from its albumin-binding sites, and consequently upregulate plasma bilirubin. Daily dosages play a vital role in regulating bilirubin levels. A drug with both a high protein binding capacity and high daily dosage significantly increases bilirubin levels in infants. Premature or very low birth weight (VLBW) infants are vulnerable to the upregulation of bilirubin levels as they exhibit the lowest reserve albumin levels and consequently the highest bilirubin toxicity index. Because bilirubin is involved in maintaining the balance between pro-oxidant and antioxidant agents, the downregulation of bilirubin levels is not always desirable. This review provides insights into the impact of protein binding capacity and daily dosage of drugs on the bilirubin levels in susceptible infants.

Multi-dimensional plasmonic coupling system for efficient enrichment and ultrasensitive label-free SERS detection of bilirubin based on graphene oxide-Au nanostars and Au@Ag nanoparticles

Rapid and sensitive detection of free bilirubin (BR) is essential for early diagnosis of jaundice and other hepatobiliary diseases. Inspired by sandwich immunoassay strategy, a multi-dimensional plasmonic coupling SERS platform composed of graphene oxide-Au nanostars nanocomposites (GANS NCs) and Au@Ag nanoparticles (NPs) was designed for label-free detection of BR. Specifically, GANS NCs were first prepared, and their excellent SERS activity was ascribed to synergistic enhancement effect of electromagnetic enhancement and chemical enhancement. Furthermore, SERS spectroscopy was used to monitor the adsorption process of BR. Subsequently, secondary reinforcing Au@Ag NPs were directly added, ultimately resulting in a multi-dimensional plasmonic coupling effect. The SERS enhancing mechanism of coupled system was discussed through electromagnetic field simulations. Interestingly, the high-density hotspots generated by strong plasmonic coupling in GANS-Au@Ag substrate could lead to more extraordinary SERS enhancing behavior compared to GANS NCs. Sensing efficiency of the SERS platform was examined by BR with a detection limit down to 10−11 M. Besides, GANS-Au@Ag NCs performed high uniformity and reproducibility. This work not only opens up a new avenue for construction of multi-dimensional plasmonic coupling system, but also offers a new biosensing technology for label-free diagnosis of BR-related diseases, thereby expecting to be applied in clinical diagnosis.

Neonatal hyperbilirubinemia differentially alters the neurochemical profiles of the developing cerebellum and hippocampus in a preterm Gunn rat model.

Neonatal hyperbilirubinemia (NHB) can lead to brain injury in newborn infants by affecting specific regions including the cerebellum and hippocampus. Extremely preterm infants (EPT) are more vulnerable to bilirubin neurotoxicity, but the mechanism and extent of injury is not well understood. A preterm version of Gunn rat model was utilized to investigate severe preterm NHB. Homozygous/jaundiced Gunn rat pups were injected (i.p.) on postnatal day (P) 5 with sulfadimethoxine, which increases serum free bilirubin capable of crossing blood brain barrier and causing brain injury. The neurochemical profiles of the cerebellum and hippocampus were determined using in vivo 1 H MRS at 9.4T on P30 and compared with heterozygous/non-jaundiced control rats. Transcript expression of related genes were determined by real-time quantitative PCR. MRI revealed significant morphological changes in the cerebellum of jaundiced rats. The concentrations of myo-inositol (+54%), glucose (+51%), N-acetylaspartylglutamate (+21%), and the sum of glycerophosphocholine and phosphocholine (+17%) were significantly higher in cerebellum of the jaundiced group compared with control group. Despite the lack of morphologic changes in the hippocampus, the concentration of myo-inositol (+9%) was higher and the concentration of creatine (-8%) and of total creatine (-3%) were lower in the jaundiced group. In the hippocampus, expression of calcium/calmodulin dependent protein kinase II alpha (Camk2a), glucose transporter (Glut) 1, and Glut3 transcripts were downregulated in the jaundiced group. In the cerebellum, the expression of glial fibrillary acidic protein (Gfap), myelin basic protein (Mbp), and Glut1 transcript expression was upregulated in the jaundiced group. These results indicate osmotic imbalance, gliosis, changes in energy utilization and myelination and demonstrate that preterm NHB critically affects brain development in a region-specific manner, with the cerebellum more severely impacted than the hippocampus.

Amino-rich nanofiber membrane with favorable hemocompatibility for highly efficient removal of bilirubin from plasma

Bilirubin is a serious toxin in the blood of liver failure patients, and the development of bilirubin adsorbent with high removal efficiency, excellent hemocompatibility is crucial to improve the efficacy of hemoperfusion therapy. Herein, PAN/PEI nanofiber membrane (NFM) with amino-rich and smooth surface structure was prepared through a more facile co-blended electrospun method. During simulated adsorption experiments in vitro, PAN/PEI NFMs exhibited a high adsorption capacity of 142.79 mg g−1 for free bilirubin at clinical bilirubin concentration (100 mg L-1) in patients with liver failure. In addition, the bilirubin removal efficiency in static adsorption exceeded 96% when the PAN/PEI NFMs addition was greater than 120 mg. In particular, PAN/PEI NFMs displayed excellent hemocompatibility, presented a low hemolysis rate (0.4%), favorable anti-adhesion properties for hemocyte and plasma protein, and had no significant effect on coagulation. The development of this facile method promotes the feasibility of nanofibrous membranes for the treatment of hyperbilirubinemia with significant implications for improving therapeutic efficacy.

Blood ACE Phenotyping for Personalized Medicine: Revelation of Patients with Conformationally Altered ACE.

Background: The angiotensin-converting enzyme (ACE) metabolizes a number of important peptides participating in blood pressure regulation and vascular remodeling. Elevated blood ACE is a marker for granulomatous diseases and elevated ACE expression in tissues is associated with increased risk of cardiovascular diseases. Objective and Methodology: We applied a novel approach -ACE phenotyping-to find a reason for conformationally impaired ACE in the blood of one particular donor. Similar conformationally altered ACEs were detected previously in 2-4% of the healthy population and in up to 20% of patients with uremia, and were characterized by significant increase in the rate of angiotensin I hydrolysis. Principal findings: This donor has (1) significantly increased level of endogenous ACE inhibitor in plasma with MW less than 1000; (2) increased activity toward angiotensin I; (3) M71V mutation in ABCG2 (membrane transporter for more than 200 compounds, including bilirubin). We hypothesize that this patient may also have the decreased level of free bilirubin in plasma, which normally binds to the N domain of ACE. Analysis of the local conformation of ACE in plasma of patients with Gilbert and Crigler-Najjar syndromes allowed us to speculate that binding of mAbs 1G12 and 6A12 to plasma ACE could be a natural sensor for estimation of free bilirubin level in plasma. Totally, 235 human plasma/sera samples were screened for conformational changes in soluble ACE. Conclusions/Significance: ACE phenotyping of plasma samples allows us to identify individuals with conformationally altered ACE. This type of screening has clinical significance because this conformationally altered ACE could not only result in the enhancement of the level of angiotensin II but could also serve as an indicator of free bilirubin levels.

Glucose-6-Phosphate Dehydrogenase Deficiency in Icteric Newborns at the Essos-Yaound&amp;#233;-Cameroon Hospital

Background: Glucose-6-phosphate dehydrogenase deficiency is an enzymopathy characterized by insufficient production of reduced glutathione (GSH), a molecule known for its antioxidant role. This lack of GSH leads to a deficit in the elimination of peroxide ions from the red blood cells, causing thereby hemolytic accidents, which can be fatal if not properly managed. In neonates, the clinical picture is most often that of neonatal jaundice. Objectives: This study aimed to determine the place of G6PD deficiency as a cause of neonatal jaundice at Essos Hospital Centre. Methods: We conducted a prospective descriptive study over three months. Blood samples taken from newborns aged 0 to 28 days were analyzed in the medical analysis laboratory of the Essos Hospital Centre in Yaoundé. We carried out a determination of the enzymatic activity of G6PD, a blood count and the determination of the bilirubin level. The results obtained were analysed using R statistical software version 4.1.1. Linear regression analyses were used to assess correlations between the variables of interest. Results: Sixty-nine icteric neonates constituted our study population, with a total of 40 boys (58%) and 29 girls (42%) with a sex ratio of 1.37 in favour of boys. The prevalence of G6PD deficiency in icteric children was 50.72%. The mean hemoglobin was 15.3 ± 3.08 g/dL and the mean red blood cell count was 4.52 ± 1.01 × 106/mm3. The mean total bilirubin was 122 ± 48.3 mg/L with a maximum of 308 mg/L and the mean free bilirubin was 104 ± 46.6 mg/L with a maximum of 292 mg/L. Furthermore, after linear regression analysis, we obtained a positive and significant correlation between G6PD enzymatic activity and hemoglobin level (r = 0.33; p ≤ 0.001), G6PD red blood cell level (r = 0.26; p Conclusion: Neonatal jaundice in G6PD-deficient children is a real public health problem and the prevention of hemolysis in children requires an early diagnosis of the enzyme disorder and good follow-up of the children.