High unbound bilirubin for age: a neurotoxin with major effects on the developing brain

Bilirubin Molecular Species Play an Important Role in the Pathophysiology of Acute-on-Chronic Liver Failure

Bilirubin plays a key role in early diagnosis, prognosis, and prevention of liver diseases. Unconjugated bilirubin (UCB) requires conversion to a water-soluble form through liver glucuronidation, producing monoglucuronide (BMG) or diglucuronide bilirubin (BDG) for bile excretion. This study aimed to assess the roles of bilirubin's molecular species-UCB, BMG, and BDG-in diagnosing and understanding the pathogenesis of liver cirrhosis in patients with acute-on-chronic liver failure (ACLF), compensated liver cirrhosis (LC) patients, and healthy individuals. The study included patients with ACLF and compensated LC of diverse etiologies, along with healthy controls. We collected laboratory and clinical data to determine the severity and assess mortality. We extracted bilirubin from serum samples to measure UCB, BMG, and BDG using liquid chromatography-mass spectrometry (LC-MS). The quantification of bilirubin was performed by monitoring the mass charge (m/z) ratio. Of the 74 patients assessed, 45 had ACLF, 11 had LC, and 18 were healthy individuals. Among ACLF patients, the levels of molecular species of bilirubin were UCB 19.69 μmol/L, BMG 47.71 μmol/L, and BDG 2.120 μmol/L. For compensated cirrhosis patients, the levels were UCB 11.29 μmol/L, BMG 1.49 μmol/L, and BDG 0.055 μmol/L, and in healthy individuals, the levels were UCB 6.42 μmol/L, BMG 0.52 μmol/L, and BDG 0.028 μmol/L. The study revealed marked elevations in the bilirubin species in individuals with ACLF compared to those with compensated cirrhosis and healthy controls, underscoring the progression of liver dysfunction. The correlation of BMG and BDG levels with commonly used inflammatory markers suggests a relationship between bilirubin metabolism and systemic inflammation in ACLF.

Docosahexaenoic Acid Supplementation for Neonatal Hyperbilirubinemia: A Double-Blind, Randomized Clinical Trial

Docosahexaenoic acid (DHA) is an essential component for brain development during fetal and early postnatal life. Hyperbilirubinemia is characterized by abnormally high levels of bilirubin in the bloodstream, frequently leading to jaundice in newborns. In severe instances, this condition can progress to neurological damage or kernicterus, a form of brain damage. Initial cell-based experiments conducted by our research team revealed that DHA significantly enhances the survival rate of nerve cells treated with bilirubin and diminishes the oxidative stress indicated by reduced peroxide activity caused by unconjugated bilirubin (UCB). Further investigations through animal studies demonstrated that DHA effectively mitigates bilirubin-induced brain injury in neonatal rats. However, the potential of DHA to decrease the incidence of bilirubin-induced brain damage in clinical settings has not been previously explored or reported. Infants with neonatal hyperbilirubinemia (n = 30 per group) participated in a double-blind, randomized, placebo-controlled parallel study. They received either 100 mg/d DHA or placebo syrup immediately when they were diagnosed. The study found that the bilirubin level at 48 hours of treatment, serum neuron-specific enolase (NSE) levels, mean phototherapy duration, and abnormal rate of cranial magnetic resonance imaging (MRI) were lower in the DHA group than those in the control group (P < .05). These results suggested that DHA is effective as an adjuvant treatment for hyperbilirubinemia in children. It can reduce the incidence of neonatal hyperbilirubinemia brain injury and plays a certain protective role. Clinical study on protective effect of DHA on neonatal bilirubin injury is registered at Chinese Clinical Trial Registry as ChiCTR2300070250.

Bilirubin impairs neuritogenesis and synaptogenesis in NSPCs by downregulating NMDAR-CREB-BDNF signaling

Neonatal jaundice is one of the most common disorders in the first 2 wk after birth. Unconjugated bilirubin (UCB) is neurotoxic and can cause neurological dysfunction; however, the underlying mechanisms remain unclear. Neurogenesis, neuronal growth, and synaptogenesis are exuberant in the early postnatal stage. In this study, the impact of UCB on neuritogenesis and synaptogenesis in the early postnatal stage was evaluated both in vitro and in vivo. Primary culture neuronal stem and progenitor cells (NSPCs) were treated with UCB during differentiation, and then the neurite length and synapse puncta were measured. In the bilirubin encephalopathy (BE) animal model, DCX+-marked developing neurons were used to detect apical length and dendritic arborization. According to the data, UCB significantly reduced neurite length and synapse density, as well as decreased the apical dendrite length and dendritic arborization. Furthermore, the NMDAR subunit NR2B was downregulated in NSPCs, while pCREB expression in the hippocampus progressively decreased during disease progression in the BE model. Next, we tested the expression of NR2B, pCREB, mBDNF, and p-mTOR in NSPCs in vitro, and found that UCB treatment reduced the expression of these proteins. In summary, this suggests that UCB causes chronic neurological impairment and is related to the inhibition of NMDAR-CREB-BDNF signaling in NSPCs, which is associated with reduced neuritogenesis and synaptogenesis. This finding may inspire the development of novel pharmaceuticals and treatments.

Spectral analysis with highly collimated mini-LEDs as light sources for quantitative detection of direct bilirubin

Because the human eye cannot visually detect the results of direct bilirubin test papers accurately and quantitatively, this study proposes four different highly collimated mini light-emitting diodes (HC mini-LEDs) as light sources for detection. First, different concentrations of bilirubin were oxidized to biliverdin by FeCl3 on the test paper, and pictures were obtained with a smartphone. Next, the red, green, and blue (RGB) channels of the pictures were separated to average grayscale values, and their linear relationship with the direct bilirubin concentration was analyzed to detect bilirubin on the test paper noninvasively and quantitatively. The experimental results showed that when green HC mini-LEDs were used as the light sources and image analysis was performed using the G channel, for a direct bilirubin concentration range of 0.1-2 mg/dL, the G channel determination coefficient (R2) reached 0.9523 and limit of detection was 0.459 mg/dL. The detection method proposed herein has advantages such as rapid analysis, noninvasive detection, and digitization according to RGB grayscale changes in the images of the detection test paper.

Associations between neonatal jaundice and autism spectrum disorder or attention deficit hyperactivity disorder: Nationwide population based cohort study

BACKGROUND/PURPOSE

Neonatal jaundice might result brain insults. Both autistic spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) are developmental disorders, which might result from early brain injury at neonatal period. We aimed to explore the association between neonatal jaundice treated with phototherapy and the ASD or ADHD.

METHODS

This retrospective nationwide population cohort study was based on a nationally representative database of Taiwan, and neonates born from 2004 to 2010 were enrolled. All eligible infants were divided into 4 groups, without jaundice, jaundice with no treatment, jaundice with simple phototherapy only and jaundice with intensive phototherapy or blood exchange transfusion (BET). Each infant was follow-up until the date of incident primary outcomes, death, or 7-year-old, whichever occurred first. Primary outcomes were ASD, ADHD. Using cox proportional hazard model to analyze their associations.

RESULTS

In total, 118,222 infants with neonatal jaundice were enrolled, including diagnosed only (7260), simple phototherapy (82,990), intensive phototherapy or BET (27,972 infants). The cumulative incidences of ASD in each group was 0.57%, 0.81%, 0.77%, and 0.83%, respectively. The cumulative incidences of ADHD in each group was 2.83%, 4.04%, 3.52% and 3.48%, respectively. Jaundice groups were significantly associated with ASD, ADHD, or either one, even after all other extraneous maternal and neonatal variables were adjusted. After stratification, the associations were still existed in subgroup with birth weights ≥2500 grams and in male subgroup.

CONCLUSION

Neonatal jaundice correlated with the ASD and ADHD. The associations were significant in infants of both sexes and with birth weights larger than 2500 grams.

Bilirubin and Redox Stress in Age-Related Brain Diseases

Cellular redox status has a crucial role in brain physiology, as well as in pathologic conditions. Physiologic senescence, by dysregulating cellular redox homeostasis and decreasing antioxidant defenses, enhances the central nervous system's susceptibility to diseases. The reduction of free radical accumulation through lifestyle changes, and the supplementation of antioxidants as a prophylactic and therapeutic approach to increase brain health, are strongly suggested. Bilirubin is a powerful endogenous antioxidant, with more and more recognized roles as a biomarker of disease resistance, a predictor of all-cause mortality, and a molecule that may promote health in adults. The alteration of the expression and activity of the enzymes involved in bilirubin production, as well as an altered blood bilirubin level, are often reported in neurologic conditions and neurodegenerative diseases (together denoted NCDs) in aging. These changes may predict or contribute both positively and negatively to the diseases. Understanding the role of bilirubin in the onset and progression of NCDs will be functional to consider the benefits vs. the drawbacks and to hypothesize the best strategies for its manipulation for therapeutic purposes.

Bilirubin Induces A1-Like Reactivity of Astrocyte

Astrocytes play an important role in the pathogenesis of bilirubin neurotoxicity, and activated astrocytes might be potential mediators of neuroinflammation processes contributing to neuronal cell death and tissue injury. Recent studies have reported that activated microglia induce two types of reactive astrocytes. A1 astrocytes could cause neuronal death and synaptic damage, as well as impaired phagocytosis. Therefore, the purpose of this study was to investigate whether unconjugated bilirubin (UCB)-induced A1-like astrocytes take on a neuroinflammation type and the underlying regulatory mechanisms. In this study, primary cortical astrocytes were treated with UCB in vitro. We detected the expression of complement component 3 (C3), S100 calcium binding protein A10 (S100A10), nuclear factor kappa B (NF-κB), NLR family pyrin domain containing 3 (NLRP3), activated caspase-1, gasdermin D N-terminal (GSDMD-N), PSD95, synaptophysin (SYP), the transcription levels of interleukin (IL)-1β and IL-18, and the survival rate of astrocytes after UCB treatment. The results showed that an increase in C3 was accompanied by a decrease in S100A10, and that A1-like astrocytes were functionally expressed after UCB stimulation. Meanwhile, the NF-κB and caspase-1 pathways were activated after UCB stimulation. After adding the NF-κB-specific inhibitor trans-activator of transcriptional-NEMO-binding domain (TAT-NBD) and caspase-1 specific inhibitor VX-765, the survival rate of astrocytes and neurons increased, whereas the protein expression of C3, NF-κB, NLRP3, activated caspase-1, and GSDMD-N decreased, and the mRNA levels of IL-1β and IL-18 reduced. Thus, we concluded that UCB stimulates the activation of A1-like astrocytes. Inhibition of NF-κB and caspase-1 alleviated A1-like astrocytes and exerted anti-inflammatory protective effects.

Chemoprevention of bilirubin encephalopathy with a nanoceutical agent

BACKGROUND

Targeted rapid degradation of bilirubin has the potential to thwart incipient bilirubin encephalopathy. We investigated a novel spinel-structured citrate-functionalized trimanganese tetroxide nanoparticle (C-Mn3O4 NP, the nanodrug) to degrade both systemic and neural bilirubin loads.

METHOD

Severe neonatal unconjugated hyperbilirubinemia (SNH) was induced in neonatal C57BL/6j mice model with phenylhydrazine (PHz) intoxication. Efficiency of the nanodrug on both in vivo bilirubin degradation and amelioration of bilirubin encephalopathy and associated neurobehavioral sequelae were evaluated.

RESULTS

Single oral dose (0.25 mg kg-1 bodyweight) of the nanodrug reduced both total serum bilirubin (TSB) and unconjugated bilirubin (UCB) in SNH rodents. Significant (p < 0.0001) UCB and TSB-degradation rates were reported within 4-8 h at 1.84 ± 0.26 and 2.19 ± 0.31 mg dL-1 h-1, respectively. Neural bilirubin load was decreased by 5.6 nmol g-1 (p = 0.0002) along with improved measures of neurobehavior, neuromotor movements, learning, and memory. Histopathological studies confirm that the nanodrug prevented neural cell reduction in Purkinje and substantia nigra regions, eosinophilic neurons, spongiosis, and cell shrinkage in SNH brain parenchyma. Brain oxidative status was maintained in nanodrug-treated SNH cohort. Pharmacokinetic data corroborated the bilirubin degradation rate with plasma nanodrug concentrations.

CONCLUSION

This study demonstrates the in vivo capacity of this novel nanodrug to reduce systemic and neural bilirubin load and reverse bilirubin-induced neurotoxicity. Further compilation of a drug-safety-dossier is warranted to translate this novel therapeutic chemopreventive approach to clinical settings.

IMPACT

None of the current pharmacotherapeutics treat severe neonatal hyperbilirubinemia (SNH) to prevent risks of neurotoxicity. In this preclinical study, a newly investigated nano-formulation, citrate-functionalized Mn3O4 nanoparticles (C-Mn3O4 NPs), exhibits bilirubin reduction properties in rodents. Chemopreventive properties of this nano-formulation demonstrate an efficacious, efficient agent that appears to be safe in these early studies. Translation of C-Mn3O4 NPs to prospective preclinical and clinical trials in appropriate in vivo models should be explored as a potential novel pharmacotherapy for SNH.

Noninvasive direct bilirubin detection by spectral analysis of color images using a Mini-LED light source

Urine test paper is a standard, noninvasive detection method for direct bilirubin, but this method can only achieve qualitative analysis and cannot achieve quantitative analysis. This study used Mini-LEDs as the light source, and direct bilirubin was oxidized to biliverdin by an enzymatic method with ferric chloride (FeCl₃) for labeling. Images were captured with a smartphone and evaluated for red (R), green (G), and blue (B) colors to analyze the linear relationship between the spectral change of the test paper image and the direct bilirubin concentration. This method achieved noninvasive detection of bilirubin. The experimental results demonstrated that Mini-LEDs can be used as the light source to analyze the grayscale value of the image RGB. For the direct bilirubin concentration range of 0.1-2 mg/dL, the green channel had the highest coefficient of determination coefficient (R²) of 0.9313 and a limit of detection of 0.56 mg/dL. With this method, direct bilirubin concentrations higher than 1.86 mg/dL can be quantitatively analyzed with the advantage of rapid and noninvasive detection.

Development and evaluation clinical-radiomics analysis based on T1-weighted imaging for diagnosing neonatal acute bilirubin encephalopathy

Purpose

To investigate the value of clinical-radiomics analysis based on T1-weighted imaging (T1WI) for predicting acute bilirubin encephalopathy (ABE) in neonates.

Methods

In this retrospective study, sixty-one neonates with clinically confirmed ABE and 50 healthy control neonates were recruited between October 2014 and March 2019. Two radiologists' visual diagnoses for all subjects were independently based on T1WI. Eleven clinical and 216 radiomics features were obtained and analyzed. Seventy percent of samples were randomly selected as the training group and were used to establish a clinical-radiomics model to predict ABE; the remaining samples were used to validate the performance of the models. The discrimination performance was assessed by receiver operating characteristic (ROC) curve analysis.

Results

Seventy-eight neonates were selected for training (median age, 9 days; interquartile range, 7-20 days; 49 males) and 33 neonates for validation (median age, 10 days; interquartile range, 6-13 days; 24 males). Two clinical features and ten radiomics features were finally selected to construct the clinical-radiomics model. In the training group, the area under the ROC curve (AUC) was 0.90 (sensitivity: 0.814; specificity: 0.914); in the validation group, the AUC was 0.93 (sensitivity: 0.944; specificity: 0.800). The AUCs of two radiologists' and the radiologists' final visual diagnosis results based on T1WI were 0.57, 0.63, and 0.66, respectively. The discriminative performance of the clinical-radiomics model in the training and validation groups was increased compared to the radiologists' visual diagnosis (P < 0.001).

Conclusions

A combined clinical-radiomics model based on T1WI has the potential to predict ABE. The application of the nomogram could potentially provide a visualized and precise clinical support tool.

Effects of bacterial and viral pathogen-associated molecular patterns (PAMPs) on multidrug resistance (MDR) transporters in brain endothelial cells of the developing human blood-brain barrier

BACKGROUND

The multidrug resistance (MDR) transporters, P-glycoprotein (P-gp, encoded by ABCB1) and breast cancer resistance protein (BCRP/ABCG2) contribute to the blood-brain barrier (BBB), protecting the brain from drug exposure. The impact of infection on MDR in the developing human BBB remains to be determined. We hypothesized that exposure to bacterial and viral pathogen-associated molecular patterns (PAMPs) modify MDR expression and activity in human fetal brain endothelial cells (hfBECs) isolated from early and mid-gestation brain microvessels.

METHODS

We modelled infection (4 h and 24 h) using the bacterial PAMP, lipopolysaccharide (LPS; a toll-like receptor [TLR]-4 ligand) or the viral PAMPs, polyinosinic polycytidylic acid (Poly I:C; TLR-3 ligand) and single-stranded RNA (ssRNA; TLR-7/8 ligand). mRNA expression was assessed by qPCR, whereas protein expression was assessed by Western blot or immunofluorescence. P-gp and BCRP activity was evaluated by Calcein-AM and Chlorin-6 assays.

RESULTS

TLRs-3,4 and 8 were expressed by the isolated hfBECs. Infection mimics induced specific pro-inflammatory responses as well as changes in P-gp/ABCB1 or BCRP/ABCG2 expression (P < 0.05). LPS and ssRNA significantly decreased P-gp activity at 4 and 24 h in early and mid-gestation (P < 0.03-P < 0.001), but significantly increased BCRP activity in hfBECs in a dose-dependent pattern (P < 0.05-P < 0.002). In contrast, Poly-IC significantly decreased P-gp activity after 4 h in early (P < 0.01) and mid gestation (P < 0.04), but not 24 h, and had no overall effect on BCRP activity, though BCRP activity was increased with the highest dose at 24 h in mid-gestation (P < 0.05).

CONCLUSIONS

Infectious PAMPs significantly modify the expression and function of MDR transporters in hfBECs, though effects are PAMP-, time- and dose-specific. In conclusion, bacterial and viral infections during pregnancy likely have profound effects on exposure of the fetal brain to physiological and pharmacological substrates of P-gp and BCRP, potentially leading to altered trajectories of fetal brain development.

Causal relationships of neonatal jaundice, direct bilirubin and indirect bilirubin with autism spectrum disorder: A two-sample Mendelian randomization analysis

Background

Multiple systematic reviews and meta-analyses have examined the association between neonatal jaundice and autism spectrum disorder (ASD) risk, but their results have been inconsistent. This may be because the included observational studies could not adjust for all potential confounders. Mendelian randomization study can overcome this drawback and explore the causal relationship between the both.

Methods

We used the data of neonatal jaundice, direct bilirubin (DBIL), indirect bilirubin (IBIL), and ASD collected by genome-wide association study (GWAS) to evaluate the effects of neonatal jaundice, DBIL and IBIL on ASD by using a two-sample Mendelian randomized (MR). The inverse variance-weighted method (IVW) was the main method of MR analysis in this study. Weighted median method, MR-Egger regression and mendelian randomization pleiotropy residual sum and outlier (MR-PRESSO) test were used for sensitivity analysis.

Results

There was no evidence of an effect of neonatal jaundice (OR, 1.002, 95% CI, 0.977-1.027), DBIL (OR, 0.970, 95% CI, 0.884-1.064) and IBIL (OR, 1.074, 95% CI, 0.882-1.308) on ASD risk by IVW test. In the weighted median method, MR-Egger regression and leave-one-out analysis, the results were robust and no heterogeneity or pleiotropy was observed.

Conclusions

We found that neonatal jaundice, DBIL and IBIL were not associated with ASD in this study. However, this paper did not explore the effect of severity and duration of jaundice on ASD in different ethnic populations, which may require further research.

Role of transcranial Doppler in assessment of cerebral blood flow in full term neonates with extreme unconjugated hyperbilirubinemia

PURPOSE

To evaluate the difference in cerebral blood flow in neonates with and without extreme unconjugated hyperbilirubinemia.

METHODS

Transcranial Doppler parameters of 26 full term newborns with extreme unconjugated hyperbilirubinemia (UCH) were compared to 13 postnatal age and sex matched normal healthy neonates serving as controls. Resistance index (RI), pulsatility index (PI) and peak systolic velocity (PSV) were measured in the middle cerebral, internal carotid and posterior cerebral arteries on both sides by transcranial color Doppler ultrasound.

RESULTS

An increase in cerebral blood flow (decreased RI, PI and increased PSV) was observed in the extreme unconjugated hyperbilirubinemia (UCH) group. There was positive correlation between total serum bilirubin level and peak systolic velocity and vice versa with resistivity and pulsatility indices. Eight neonates developed clinical features of acute bilirubin encephalopathy and showed significantly increased peak systolic velocity in the right middle cerebral artery compared to those with normal outcome. Resistivity index and pulsatility index were lower in patients managed by exchange transfusion compared to those managed with phototherapy.

CONCLUSION

An increase in cerebral blood flow was observed in neonates with UCH compared to those without hyperbilirubinemia. By assessing the cerebral blood flow velocity, resistivity index (RI), and pulsatility index (PI) of particular intracranial arteries, the transcranial Doppler can identify the at-risk neonates, for development of neurological affliction in extreme unconjugated hyperbilirubinemia.

Bilirubin Encephalopathy

PURPOSE OF REVIEW

Hyperbilirubinemia is commonly seen in neonates. Though hyperbilirubinemia is typically asymptomatic, severe elevation of bilirubin levels can lead to acute bilirubin encephalopathy and progress to kernicterus spectrum disorder, a chronic condition characterized by hearing loss, extrapyramidal dysfunction, ophthalmoplegia, and enamel hypoplasia. Epidemiological data show that the implementation of universal pre-discharge bilirubin screening programs has reduced the rates of hyperbilirubinemia-associated complications. However, acute bilirubin encephalopathy and kernicterus spectrum disorder are still particularly common in low- and middle-income countries.

RECENT FINDINGS

The understanding of the genetic and biochemical processes that increase the susceptibility of defined anatomical areas of the central nervous system to the deleterious effects of bilirubin may facilitate the development of effective treatments for acute bilirubin encephalopathy and kernicterus spectrum disorder. Scoring systems are available for the diagnosis and severity grading of these conditions. The treatment of hyperbilirubinemia in newborns relies on the use of phototherapy and exchange transfusion. However, novel therapeutic options including deep brain stimulation, brain-computer interface, and stem cell transplantation may alleviate the heavy disease burden associated with kernicterus spectrum disorder. Despite improved screening and treatment options, the prevalence of acute bilirubin encephalopathy and kernicterus spectrum disorder remains elevated in low- and middle-income countries. The continued presence and associated long-term disability of these conditions warrant further research to improve their prevention and management.

[Auditory neuropathy and prematurity: modern view of the issue (literature review)]

Auditory neuropathy spectrum disorder (ANSD) is a specific auditory disorder caused by dysfunction of periphery part of the auditory system, in which the function of the outer hair cells is preserved, but the afferent input at the cochlear level suffers due to the pathology of the inner hair cells, neurons of the spiral ganglion and/or the auditory nerve, as well as synaptic contact between them. As a result, a specific condition is formed, in which a patient's otoacoustic emissions and/or cochlear microphonics are present, auditory brainstem responses are abnormal or absent, the discrepancy between the hearing level and the electrophysiological data, poor speech perception which may not correlate with the hearing thresholds. ANSD is a multifactorial disease. One of the main risk factors is perinatal pathology and, in particular, prematurity. The possible factors associated with prematurity that provoke the onset of the disease, features of the pathogenesis, clinical and audiological peculiarities of ANSD in premature infants, contemporary approaches to the habilitation of such patients are discussed in the article. The necessity of an individual, patient-oriented approach to the treatment of premature infants with ANSD is substantiated; such an approach should be based both on the genesis of the disorder, taking into account possible points of lesion in the auditory system, and the developmental peculiarities of a premature baby considering the presence of concomitant diseases associated with prematurity. In the article attention is focused on the main directions of habilitation work with such children, including a multidisciplinary approach, regular careful monitoring of the auditory, speech and language skills, intensive psychological and speech therapist support, the choice of an adequate way of intervention and its improvement as necessary.

Breastfeeding Insufficiencies: Common and Preventable Harm to Neonates

Insufficient milk intake in breastfed neonates is common, frequently missed, and causes preventable hospitalizations for jaundice/hyperbilirubinemia, hypernatremia/dehydration, and hypoglycemia - accounting for most U.S. neonatal readmissions. These and other consequences of neonatal starvation and deprivation may substantially contribute to fully preventable morbidity and mortality in previously healthy neonates worldwide. Previous advanced civilizations recognized this problem of breastfeeding insufficiencies and had an infrastructure to solve it: Wetnursing, shared nursing, and prelacteal feeding traditions used to be well-organized and widespread. Modern societies accidentally destroyed that infrastructure. Then, modern reformers missing a few generations of direct knowledge transmission about safe breastfeeding invented a new, historically anomalous conception of breastfeeding defined in terms of exclusivity. As that new intervention has become increasingly widespread, so too have researchers widely reported associated possible harms of the longer neonatal starvation/deprivation and later infant under-nutrition periods that it creates when breastfeeding is insufficient. Early insufficient nutrition/hydration has possible long-term effects including neurodevelopmental consequences such as attention deficit hyperactivity disorder, autism, cerebral palsy, cognitive and developmental delay, epilepsy, hearing impairment, kernicterus, language disorder, mood disorders, lower IQ, and specific learning disorder. Current early infant feeding guidelines conflict with the available evidence. Recent reform efforts have tended to focus on using more technology and measurement to harm fewer neonates instead of proposing the indicated paradigm shift in early infant feeding to prevent more harm. The scientific evidence is already sufficient to mandate application of the precautionary principle to feed neonates early, adequate, and often milk before mothers' milk comes in and whenever signs of hunger persist, mitigating possible risks including death or disability. In most contexts, the formula is the best supplementary milk for infants at risk from breastfeeding insufficiencies. National-level reviews of scientific evidence, health policy, and research methods and ethics are needed to initiate the early infant feeding paradigm shift that the data already support. Policy experiments and related legislative initiatives might also contribute to the shift, as insurers might decline or be required by law to decline reimbursing hospitals for costs of this type of preventable hospitalization, which otherwise generates profit.

High levels of unbound bilirubin are associated with acute bilirubin encephalopathy in post-exchange transfusion neonates

BACKGROUND

Although it is known that unbound bilirubin can enter the brain, there is little evidence of its association with the development of acute bilirubin encephalopathy. Here, we investigated this potential relationship in neonates who had undergone exchange transfusion.

METHODS

Data from 46 newborns who underwent exchange transfusion between 2016 and 1-1 to 2018-12-31 at the First People's Hospital of Changde City in China were analyzed. The unbound bilirubin level was taken as the independent variable and the development of the acute bilirubin encephalopathy as the dependent variable. The covariates were age, birth weight, sex, red blood cell count, blood glucose, hemolytic disease, and whether the infant had received phototherapy.

RESULTS

The mean age and gestational age of the neonates were 146.5 ± 86.9 h and 38.6 ± 1.3 weeks [38.7(34.6-41.1) weeks] old, respectively; 52.17% were male. Binary logistic regression analysis after adjustment for covariates showed a positive association between the levels of unbound bilirubin and the development of acute bilirubin encephalopathy (odds ratio = 1.41, 95% confidence intervals 1.05-1.91, P = < 0.05).

CONCLUSION

There is a significant association between unbound bilirubin levels and the development of acute bilirubin encephalopathy in neonates. Further investigations are required to explore the mechanisms.

Acetaminophen elevates unbound bilirubin levels by the glucose oxidase-peroxidase method

BACKGROUND

Acetaminophen is widely administered to neonates but its effect on unbound bilirubin (UB) levels remains unclear. The aim of this study was to clarify whether administration of acetaminophen is related to an elevation of UB levels.

METHOD

Infants with a birthweight of ˂1,500 g admitted to our neonatal intensive care unit between January 2017 and April 2020 were retrospectively reviewed. Seventy-one infants were enrolled, five of whom had received acetaminophen. Clinical data were analyzed when the highest UB value (UB peak) in each infant was recorded. Demographic data and information on treatment within the 24 h before the UB peak were also collected. UB was determined by the glucose oxidase-peroxidase (GOD-POD) method. Infants were categorized according to the presence or absence of acetaminophen administration (acetaminophen and no acetaminophen groups) within 24 h of the UB peak. The relationship between UB values and various clinical variables was then compared.

RESULTS

Both the peak UB value and the ratio of gastrointestinal disease were higher in the acetaminophen group than in the no acetaminophen group. Univariate analysis revealed that a total of seven variables were potentially correlated with UB peak values (P < 0.10). Multivariate analysis showed that acetaminophen and direct bilirubin were independently associated with UB peak values.

CONCLUSION

Our study suggests that administration of acetaminophen is related to higher UB levels by the GOD-POD method. UB values measured by the GOD-POD method should not be used in infants treated with acetaminophen for evaluation of bilirubin neurotoxicity avoidance.

Biliverdin reductase as a target in drug research and development: Facts and hypotheses

Biliverdin reductase-A (BVR) catalyzes the reduction of heme-derived biliverdin into bilirubin, this latter being a powerful endogenous free radical scavenger. Furthermore, BVR is also endowed with both serine/threonine/tyrosine kinase and scaffold activities, through which it interacts with the insulin receptor kinase, conventional and atypical protein kinase C isoforms, mitogen-activated protein kinases as well as the phosphatidylinositol-3 kinase/Akt system. By regulating this complex array of signal transduction pathways, BVR is involved in the pathogenesis of neurodegenerative, metabolic, cardiovascular and immune-inflammatory diseases as well as in cancer. In addition, both BVR and BVR-B, this latter being an alternate isozyme predominant during fetal development but sometimes detectable through adulthood, have been studied as peripheral biomarkers for an early detection of Alzheimer's disease, atherosclerosis and some types of cancer. However, despite these interesting lines of evidence, to date BVR has not been considered as an appealing drug target. Only limited evidence supports the neuroprotective effects of atorvastatin and ferulic acid through BVR regulation in the aged canine brain and human neuroblastoma cells, whereas interesting results have been reported regarding the use of BVR-based peptides in preclinical models of cardiac diseases and cancer.

Catalogue of self-targeting nano-medical inventions to accelerate clinical trials

Repetitive outbreaks and prolonged epidemics represent mortal threats to global health, creating chaos in our globalized world. To date, scientists have been compelled to follow FDA guidelines for conventional clinical trials, which decelerates the release of effective therapies to battle outbreaks and safeguard global health security. Developing multi-purpose platform nanotechnologies to self-target specific organs in response to the disease microenvironment could greatly help to rapidly anticipate and efficiently manage outbreaks. Nano-interventions in the form of self-targeting nanoparticles (NPs) could accelerate the clinical translation of potential drugs to fight future outbreaks via innovating their clinical trials. This review sets the foundation of the self-targeting concept to govern the in vivo fate of NPs without the need to complicate the engineering designs with targeting ligands. The proposed catalogue of accelerated nano-innovations offers self-targeting, physiological trafficking, bio-compliance, and controllable drug release in response to associated smart linkers.

Effectiveness of Transcutaneous Bilirubin Measurement in High-Risk Neonates and to Evaluate Validity of Transcutaneous Bilirubin With Total Serum Bilirubin Levels in Both Low and High-Risk Neonates at a Tertiary Care Center in a Developing Country

Objectives To evaluate the usefulness of transcutaneous bilirubin (TcBR) nomogram in high-risk neonates and to identify the validity of TcBR and total serum bilirubin (TsBR) in both low and high-risk neonates to guide management in under-resourced settings. Methodology A cross-sectional study was conducted at the well-baby nursery of a tertiary care center in Karachi, Pakistan. All neonates admitted in the well-baby nursery with jaundice were stratified into high and low-risk groups. Eighty-seven neonates were included in the low-risk group and 121 neonates in the high-risk group. The usefulness of the TcBR nomogram in high-risk neonates and the validity of TcBR and TsBR in both low and high-risk neonates were determined through sensitivity and specificity analysis. Results The correlation coefficients (r) were found to be comparable in the high-risk group (r = 0.82, p < 0.001) and the low-risk group (r = 0.87, p < 0.001). The specificity of cutaneous bilirubin measurement based on bilirubin levels in the high-risk group was higher (93.0%) than that of the low-risk group (90.1%). However, the sensitivity was found to be lower (60.0%) in the high-risk group compared to the low-risk group (68.8%). The mean value of TsBR was equal in both groups. The mean TcBR in the high-risk group was 10 ± 2.3 compared to 11 ± 2.1 in the low-risk group. Phototherapy was given in 67.0% of the high-risk cases and 41.4% of the low-risk cases. Bland Altman analysis was also performed to depict the relationship between TcBR and TsBR measurements. Conclusion The TcBR nomogram was effective in high-risk neonates and also had validity in both high and low-risk neonates. A phototherapy-driven protocol based on TcBR would be a cost-effective and useful tool in the identification and management of neonatal jaundice in both high and low-risk groups in developing countries like Pakistan.

Perinatal Factors in Newborn Are Insidious Risk Factors for Childhood Autism Spectrum Disorders: A Population-based Study

We analyzed claims data from the Taiwan National Health Insurance database, which contains data of 23.5 million Taiwan residents. We included children born after January 1, 2000 who had received a diagnosis of autism spectrum disorders (ASD). Patients who were not diagnosed with ASD were included in the control group. The ASD prevalence was 517 in 62,051 (0.83%) children. Neonatal jaundice, hypoglycemia, intrauterine growth retardation (IUGR), and craniofacial anomalies (CFA) differed significantly between the ASD and control groups. After logistic regressive analysis, the adjusted odds ratios of IUGR, CFA, neonatal hypoglycemia, and neonatal jaundice were 8.58, 7.37, 3.83, and 1.32, respectively. Those insidiously perinatal risk factors, namely CFA, IUGR, neonatal hypoglycemia, and neonatal jaundice, could increase the risk of ASD.

Mechanism of bilirubin elimination in urine: insights and prospects for neonatal jaundice

Despite a century of research, bilirubin metabolism and the transport mechanisms responsible for homeostasis of bilirubin in serum remain controversial. Emerging evidence on the hepatic membrane transporters and inherited disorders of bilirubin metabolism have contributed to a greater understanding of the various steps involved in bilirubin homeostasis and its associated excretory pathways. We discuss these recent research findings on hepatic membrane transporters and evaluate their significance on the newborn bilirubin metabolism and excretion. New insights gained speculate that a proportion of conjugated bilirubin is excreted via the renal system, as an alternative to the intestinal excretion, even in normal physiological jaundice with no associated pathological concerns. Finally, this paper discusses the clinical relevance of targeting the altered renal excretory pathway, as bilirubin in urine may hold diagnostic importance in screening for neonatal jaundice.

Simultaneous evaluation of antioxidative serum profiles facilitates the diagnostic screening of autism spectrum disorder in under-6-year-old children

This case–control study aimed to assess oxidative stress alterations in autism spectrum disorder (ASD). We used the MULTIS method, an electron spin resonance-based technique measuring multiple free radical scavenging activities simultaneously, in combination with conventional oxidative stress markers to investigate the ability of this MULTIS approach as a non-behavioural diagnostic tool for children with ASD. Serum samples of 39 children with ASD and 58 age-matched children with typical development were analysed. The ASD group showed decreased hydroxyl radical (^·OH) and singlet oxygen scavenging activity with increased serum coenzyme Q10 oxidation rate, indicating a prooxidative tendency in ASD. By contrast, scavenging activities against superoxide (O₂^·−) and alkoxyl radical (RO^·) were increased in the ASD group suggesting antioxidative shifts. In the subgroup analysis of 6-year-olds or younger, the combination of ^·OH, O₂^·−, and RO^· scavenging activities predicted ASD with high odds ratio (50.4), positive likelihood (12.6), and percentage of correct classification (87.0%). Our results indicate that oxidative stress in children with ASD is not simply elevated but rather shows a compensatory shift. MULTIS measurements may serve as a very powerful non-behavioural tool for the diagnosis of ASD in children.

Two Faces of Heme Catabolic Pathway in Newborns: A Potential Role of Bilirubin and Carbon Monoxide in Neonatal Inflammatory Diseases

In an infant's body, all the systems undergo significant changes in order to adapt to the new, extrauterine environment and challenges which it poses. Fragile homeostasis can be easily disrupted as the defensive mechanisms are yet imperfect. The activity of antioxidant enzymes, i.e., superoxide dismutase, catalase, and glutathione peroxidase, is low; therefore, neonates are especially vulnerable to oxidative stress. Free radical burden significantly contributes to neonatal illnesses such as sepsis, retinopathy of premature, necrotizing enterocolitis, bronchopulmonary dysplasia, or leukomalacia. However, newborns have an important ally-an inducible heme oxygenase-1 (HO-1) which expression rises rapidly in response to stress stimuli. HO-1 activity leads to production of carbon monoxide (CO), free iron ion, and biliverdin; the latter is promptly reduced to bilirubin. Although CO and bilirubin used to be considered noxious by-products, new interesting properties of those compounds are being revealed. Bilirubin proved to be an efficient free radicals scavenger and modulator of immune responses. CO affects a vast range of processes such as vasodilatation, platelet aggregation, and inflammatory reactions. Recently, developed nanoparticles consisting of PEGylated bilirubin as well as several kinds of molecules releasing CO have been successfully tested on animal models of inflammatory diseases. This paper focuses on the role of heme metabolites and their potential utility in prevention and treatment of neonatal diseases.

Prediction of Drug-Induced Hyperbilirubinemia by In Vitro Testing

Bilirubin, the end product of heme catabolism, is produced continuously in the body and may reach toxic levels if accumulates in the serum and tissues; therefore, a highly efficient mechanism evolved for its disposition. Normally, unconjugated bilirubin enters hepatocytes through the uptake transporters organic anion transporting polypeptide (OATP) 1B1 and 1B3, undergoes glucuronidation by the Phase II enzyme UDP glucuronosyltransferase 1A1 (UGT1A1), and conjugated forms are excreted into the bile by the canalicular export pump multidrug resistance protein 2 (MRP2). Any remaining conjugated bilirubin is transported back to the blood by MRP3 and passed on for uptake and excretion by downstream hepatocytes or the kidney. The bile salt export pump BSEP as the main motor of bile flow is indirectly involved in bilirubin disposition. Genetic mutations and xenobiotics that interfere with this machinery may impede bilirubin disposition and cause hyperbilirubinemia. Several pharmaceutical compounds are known to cause hyperbilirubinemia via inhibition of OATP1Bs, UGT1A1, or BSEP. Herein we briefly review the in vitro prediction methods that serve to identify drugs with a potential to induce hyperbilirubinemia. In vitro assays can be deployed early in drug development and may help to minimize late-stage attrition. Based on current evidence, drugs that behave as mono- or multispecific inhibitors of OATP1B1, UGT1A1, and BSEP in vitro are at risk of causing clinically significant hyperbilirubinemia. By integrating inhibition data from in vitro assays, drug serum concentrations, and clinical reports of hyperbilirubinemia, predictor cut-off values have been established and are provisionally suggested in this review. Further validation of in vitro readouts to clinical outcomes is expected to enhance the predictive power of these assays.

Microglia Susceptibility to Free Bilirubin Is Age-Dependent

Increased concentrations of unconjugated bilirubin (UCB), namely its free fraction (Bf), in neonatal life may cause transient or definitive injury to neurons and glial cells. We demonstrated that UCB damages neurons and glial cells by compromising oligodendrocyte maturation and myelination, and by activating astrocytes and microglia. Immature neurons and astrocytes showed to be especially vulnerable. However, whether microglia susceptibility to UCB is also age-related was never investigated. We developed a microglia culture model in which cells at 2 days in vitro (2DIV) revealed to behave as the neonatal microglia (amoeboid/reactive cells), in contrast with those at 16DIV microglia that performed as aged cells (irresponsive/dormant cells). Here, we aimed to unveil whether UCB-induced toxicity diverged from the young to the long-cultured microglia. Cells were isolated from the cortical brain of 1- to 2-day-old CD1 mice and incubated for 24 h with 50/100 nM Bf levels, which were associated to moderate and severe neonatal hyperbilirubinemia, respectively. These concentrations of Bf induced early apoptosis and amoeboid shape in 2DIV microglia, while caused late apoptosis in 16DIV cells, without altering their morphology. CD11b staining increased in both, but more markedly in 2DIV cells. Likewise, the gene expression of HMGB1, a well-known alarmin, as well as HMGB1 and GLT-1–positive cells, were enhanced as compared to long-maturated microglia. The CX3CR1 reduction in 2DIV microglia was opposed to the 16DIV cells and suggests a preferential Bf-induced sickness response in younger cells. In conformity, increased mitochondrial mass and NO were enhanced in 2DIV cells, but unchanged or reduced, respectively, in the 16DIV microglia. However, 100 nM Bf caused iNOS gene overexpression in 2DIV and 16DIV cells. While only arginase 1/IL-1β gene expression levels increased upon 50/100 nM Bf treatment in long-maturated microglia, MHCII/arginase 1/TNF-α/IL-1β/IL-6 (>10-fold) were upregulated in the 2DIV microglia. Remarkably, enhanced inflammatory-associated microRNAs (miR-155/miR-125b/miR-21/miR-146a) and reduced anti-inflammatory miR-124 were found in young microglia by both Bf concentrations, while remained unchanged (miR/21/miR-125b) or decreased (miR-155/miR-146a/miR-124) in aged cells. Altogether, these findings support the neurodevelopmental susceptibilities to UCB-induced neurotoxicity, the most severe disabilities in premature babies, and the involvement of immune-inflammation neonatal microglia processes in poorer outcomes.

A clinical prediction rule for acute bilirubin encephalopathy in neonates with extreme hyperbilirubinemia: A retrospective cohort study

To establish a clinical prediction rule for acute bilirubin encephalopathy (ABE) in term/near-term neonates with extreme hyperbilirubinemia.A retrospective cohort study was conducted between January 2015 and December 2018. Six hundred seventy-three out of 26,369 consecutive neonates with extreme hyperbilirubinemia were enrolled in this study. Data included demographic characteristics, total serum bilirubin (TSB), albumin, bilirubin/albumin ratio (B/A), direct antiglobulin test, glucose-6-phosphate deficiency, asphyxia, sepsis, acidosis. ABE was defined as a bilirubin induced neurological dysfunction score of 4 to 9. We used stepwise logistic regression to select predictors of ABE and devised a prediction score.Of the 673 eligible infants, 10.8% suffered from ABE. Our prediction score consisted of 3 variables: TSB (as a continuous variable; odds ratio [OR] 1.16; 95% confidence interval [CI], 1.02-1.31; logistic coefficient 0.15), B/A (as a continuous variable; OR 1.88; 95% CI, 1.19-2.97; logistic coefficient 0.67), and sepsis (OR 3.78; 95% CI, 1.40-10.21; logistic coefficient 1.19). Multiplying the logistic coefficients by 10 and subtracting 75, resulted in the following equation for the score: Score = 12 × (if sepsis) + 1.5 × (TSB) + 7 × (B/A) - 75. The model performed well with an area under the curve of 0.871.The risk of ABE can be quantified according to TSB, B/A, and sepsis in term/near-term neonates with extreme hyperbilirubinemia.