Postnatal Age Research Articles

Distribution, development, and identity of retinal ganglion cells labeled in the Sert-Cre reporter mouse.

The mouse retina contains over 40 types of retinal ganglion cells (RGCs) that differ in morphology, function, or gene expression. RGCs also differ by whether their axons target the brain.s ipsilateral or contralateral hemisphere. Contralaterally projecting RGCs (contraRGCs) are widespread in mouse retina, whereas ipsilateral projecting RGCs (ipsiRGCs) are confined to the ventro-temporal (VT) crescent of retina. In this study, we employed the Sert-Cre transgenic line, which had been reported to selectively label ipsiRGCs, to study ipsiRGCs during development. Although the number of Cre-expressing ipsiRGCs did not significantly increase with postnatal age, the region of retina that they occupied did, and by adulthood represented ~30% of the retinal surface. Unexpectedly, genetic ablation of Sert-Cre cells failed to fully disrupt ipsilateral projecting retinal axons, suggesting that not all ipsiRGCs generated Cre in Sert-Cre mice. To test this hypothesis, we retrogradely labeled ipsiRGCs in Sert-Cre mice which revealed that not all ipsiRGCs are labeled in Sert-Cre mice and a small population of contraRGCs flanking the VT crescent generates Cre in this line. These results do not negate the usefulness of the Sert-Cre mouse but do raise important caveats to the interpretation of such studies.

In Rat Organotypic Hippocampal Slice Cultures, Conventional Antiepileptic Medications are Unable to Inhibit Epileptiform Activity

Context and Goal: Prior research has shown that organotypic hippocampal slice cultures (OHSCs) can elicit tonic-clinic seizure-like events (SLEs), which resemble the electroencephalographic correlates of limbic seizures in humans and animals. We have investigated whether OHSCs can be used as in vitro models of limbic seizures to research seizures processes and vetting novel antiepileptic substances. Experimental Strategy: The interface method was used to cultivate OHSCs. Under submerged conditions, the levels of extracellular potassium and neuronal activity were observed. Lowering magnesium concentrations or administering the potassium channel blocker 4-aminopyridine both caused SLEs. Analysis was done on the impact of common antiepileptic medications (AEDs) on SLEs, including carbamazepine, phenytoin, valproic acid, clonazepam, diazepam, and phenobarbital sodium. Important Outcomes: AEDs did not stop the over 93% of OHSCs from happening induction of SLEs or cease current seizure activity even in the presence of hazardous dosages. The postnatal age at explanation (P2–P10), the manner of seizure provocation, and the length of in vitro cultivation (2 months) had no bearing on this chemoresistance. GABAA-agonist muscimol or glutamate antagonists were able to reversibly block SLEs. Inferences and Conclusions: Unlike animal models of thermoresistant seizures, where responders and nonresponses may only be distinguished after an experiment, we describe an easy to set up in vitro model of tonic-clinic SLEs that is a priori thermoresistant. OHSCs may be useful for investigating the mechanisms underlying medication-resistant seizures and for the discovery of novel anticonvulsive substances that may one day be used to treat drugresistant epilepsy.

Collagen type IV alpha 1 chain (COL4A1) expression in the developing human lung

BackgroundCollagen type IV alpha 1 chain (COL4A1) in the basement membrane is an important component during lung development, as suggested from animal models where COL4A1 has been shown to regulate alveolarization and angiogenesis. Less is known about its role in human lung development. Our aim was to study COL4A1 expression in preterm infants with different lung maturational and clinical features.MethodsCOL4A1 expression in 115 lung samples from newborn infants (21-41 weeks’ gestational age; 0-228 days’ postnatal age [PNA]) was studied by immunohistochemistry combined with digital image analysis. Cluster analysis was performed to find subgroups according to immunohistologic and clinical data.ResultsPatients were automatically categorized into 4 Groups depending on their COL4A1 expression. Expression of COL4A1 was mainly extracellular in Group 1, low in Group 2, intracellular in Group 3, and both extra- and intracellular in Group 4. Intracellular/extracellular ratio of COL4A1 expression related to PNA showed a distinctive postnatal maturational pattern on days 1-7, where intracellular expression of COL4A1 was overrepresented in extremely preterm infants.ConclusionsCOL4A1 expression seems to be highly dynamic during the postnatal life due to a possible rapid remodeling of the basement membrane. Intracellular accumulation of COL4A1 in the lungs of extremely premature infants occurs more frequently between 1 and 7 postnatal days than during the first 24 hours. In view of the lung arrest described in extremely preterm infants, the pathological and/or developmental role of postnatally increased intracellular COL4A1 as marker for basement membrane turnover, needs to be further investigated.

Latamoxef dosing regimen adjustments and pharmaceutical care in pediatrics.

Latamoxef is a semi-synthetic, broad-spectrum oxacephem antibiotic used primarily to treat infectious diseases, but the adverse drug reactions, such as the risk of fatal bleeding, once caused physicians to use it less frequently. However, with the rise of antibiotic-resistant bacterial strains, latamoxef is being used again to treat infectious diseases, especially in pediatrics. The pharmacokinetic parameters of latamoxef are highly variable, given the changes in body composition, organ maturation, and development that occurs in pediatrics. Therefore, an appropriate dosing regimen is essential. Latamoxef dosing optimization in pediatrics should adequately account for current body weight, postnatal age, postmenstrual age, and different minimum inhibitory concentration (MIC) values. In addition, attention should also be paid to some of the adverse reactions associated with latamoxef, such as coagulation disorders and bleeding risks, disulfiram-like reactions, as well as hypersensitivity and anaphylactic shock. This review summarizes the dosing regimens and some key points of pharmaceutical care for latamoxef in pediatrics in order to provide a better reference for its application in clinical practice.

Inhaled nitric oxide therapy for preterm infants after 7 days of age: a scoping review protocol

IntroductionInhaled nitric oxide (iNO) use is recommended for persistent pulmonary hypertension of the newborn in term and late preterm infants. Recently, iNO therapy to prevent bronchopulmonary dysplasia (BPD) or rescue...

Evaluation of the association between patent ductus arteriosus approach and neurodevelopment in extremely preterm infants.

Assess if unit-level PDA management correlates with neurodevelopmental impairment (NDI) at 18-24 months corrected postnatal age (CPA) in extremely preterm infants. Retrospective analysis of infants born at <29 weeks (2014-2017) across two units having distinct PDA strategies. Site 1 utilized an echocardiography-based treatment strategy aiming for accelerated closure (control). Site 2 followed a conservative approach. NDI, characterized by cerebral palsy, any Bayley-III composite score <85, sensorineural/mixed hearing loss, or at least unilateral visual impairment. 377 infants were evaluated. PDA treatment rates remained unchanged in Site 1 but eventually reached 0% in Site 2. Comparable rates of any/significant NDI were seen across both sites (any NDI: 38% vs 36%; significant NDI: 13% vs 10% for Site 1 and 2, respectively). After adjustments, NDI rates remained similar. PDA management strategies in extremely preterm newborns showed no significant impact on neurodevelopment outcomes at 18-24 months CPA.

Postnatal epigenome-mediated aging control and global trends

The epigenome can adequately regulate the on/off states of genes in response to external environmental factors and stress. In recent years, it has been observed that the epigenome, which is modulated through DNA methylation, histone modifications, and chromatin remodeling, changes with age. Alterations in the epigenome lead to the loss of cell-specific epigenome/identity, which in turn triggers a decline in tissue function. In mammals, postnatal epigenomic variations are not only caused by metabolic diseases, such as diabetes or DNA damage, but also by social stress and infectious diseases. Unlike Genome-Wide Association Studies (GWAS), dynamically changing epigenomes, along with their cellular roles, need to be established as objective biomarkers in conjunction with various biological signals, such as walking speed, brain waves, and clinical data. The biological age/aging clock, determined by methylated DNA, has attracted attention, and calorie restriction not only slows the progression of aging, but also seems to suppress it. However, as indicated by gene expression analysis in aging mice, aging is not a linear model, but is represented by nonlinear dynamic changes. Consequently, the development of experimental models and analytical methods that enhance temporal resolution through time-series analysis, tailored to spatial resolution, such as cell distribution and organ specificity, is progressing. Moreover, in recent years, in addition to anti-aging efforts targeting epigenomic variations, global attention has increasingly focused on research and development aimed at rejuvenating treatments, thus leading to the birth of many biotech companies. Aging Hallmarks such as inflammation, stem cells, metabolism, genomic instability, and autophagy, interact closely with the epigenome. Various postnatal and reversible epigenomic controls of aging, including Yamanaka factors (OKSM and OSK), are now entering a new phase. In the future, the development of aging control using diverse modalities, such as mRNA, artificial peptides, and genome editing, is expected, along with an improved molecular understanding of aging and identification of useful biomarkers.

Parenteral Nutrition-Associated Sepsis and Extravasation in Iraqi Neonates: Case-Series Prospective Study

Background: Extravasation and sepsis are two of the many side effects linked to the use of intravascular devices during parenteral nutrition (PN). Objective: To assess the incidence of sepsis and extravasation in Iraqi neonates receiving PN in the critical care unit. Methods: From January 27, 2022, to January 15, 2023, a case-series prospective study was carried out in two tertiary neonatal intensive care units (NICUs) in Children Welfare Hospital and Baghdad Teaching Hospital, Baghdad, Iraq. The study reports the rate of sepsis and extravasations and correlates their occurrence to other neonatal features. Results: Of the 94 newborns examined, 24 patients (25.5%) experienced 35 instances of stage IV extravasation, and 34.04% of them experienced 40 episodes of sepsis in total. They have a strong and significant correlation with the newborns' body weight, treatment duration, gestational age, and postnatal age. Conclusions: The administration of PN to neonates in Iraq has been linked to severe side effects such as sepsis and extravasation.

A pilot study of fecal pH and redox as functional markers in the premature infant gut microbiome.

The infant gut microbiome is a crucial factor in health and development. In preterm infants, altered gut microbiome composition and function have been linked to serious neonatal complications such as necrotizing enterocolitis and sepsis, which can lead to long-term disability. Although many studies have described links between microbiome composition and disease risk, there is a need for biomarkers to identify infants at risk of these complications in practice. In this pilot study, we obtained stool samples from preterm infant participants longitudinally during the first postnatal months, and measured pH and redox, as well as SCFA content and microbiome composition by 16S rRNA gene amplicon sequencing. These outcomes were compared to clinical data to better understand the role of pH and redox in infant gut microbiome development and overall health, and to assess the potential utility of pH and redox as biomarkers. We found that infants born earlier or exposed to antibiotics exhibited increased fecal pH, and that redox potential increased with postnatal age. These differences may be linked to changes in SCFA content, which was correlated with pH and increased with age. Microbiome composition was also related to birth weight, age, pH, and redox. Our findings suggest that pH and redox may serve as biomarkers of metabolic state in the preterm infant gut.

Need for Repeat-Hospitalization in Very Low Birth Weight or Very Preterm Infants: A Prospective Cohort Study.

To determine the incidence of repeat-hospitalization amongst neonates with gestation <32 wk or birth weight <1500g within 6 mo of birth. All live births with gestation <32 wk or birth weight <1500g born at a level-III NICU were prospectively enrolled and followed up through routine visits, multimedia and telephonically, fortnightly for re-hospitalization details till 6 mo of postnatal age. Main outcome measures were incidence, causes and risk factors for repeat-hospitalization. Of the 131 neonates enrolled, incidence and incidence density ofrepeat-hospitalization were 16% (95% CI 10.2-23.4) and 3.6 per 100 person-months, respectively. The most common causes for repeat-hospitalizations were pneumonia (n = 8; 29.6%), sepsis (n = 5, 18.5%), gastroenteritis (n = 3, 11.1%) and severe anemia (n = 2, 7.4%). Majority of repeat-hospitalizations (92.6%; 95% CI 74.1-98.5) occurred within 2 mo of discharge. The median hospital stay during repeat-hospitalizations was 4 d (IQR 1-21). On multivariate analysis, lower socioeconomic status was significantly associated with repeat-hospitalization (aOR 5.9, 1.3-23). Death after discharge occurred in 3 (2.3%) infants and were due to sudden infant death syndrome, complex cyanotic heart disease and pneumonia with multiple co-morbidities (one each). All deaths occurred at home. Nearly one-sixth of very low birth weight (VLBW) or very preterm infants required repeat-hospitalization after discharge, primarily within 2 mo of discharge. Infections, especially pneumonia, being the most common reason. A comprehensive follow-up package of post-discharge care for prevention of morbidities and timely hospital care for ongoing morbidities is required for optimal long-term survival of these infants.

NRF2 is required for neonatal mouse beta cell growth by maintaining redox balance and promoting mitochondrial biogenesis and function.

All forms of diabetes result from insufficient functional beta cell mass. Due to the relatively limited expression of several antioxidant enzymes, beta cells are highly vulnerable to pathological levels of reactive oxygen species (ROS), which can lead to the reduction of functional beta cell mass. During early postnatal ages, both human and rodent beta cells go through a burst of proliferation that quickly declines with age. The exact mechanisms that account for neonatal beta cell proliferation are understudied but mitochondrial release of moderated ROS levels has been suggested as one of the main drivers. We previously showed that, apart from its conventional role in protecting beta cells from oxidative stress, the nuclear factor erythroid 2-related factor 2 (NRF2) is also essential for beta cell proliferation. We therefore hypothesised that NRF2, which is activated by ROS, plays an essential role in beta cell proliferation at early postnatal ages. Beta cell NRF2 levels and beta cell proliferation were measured in pancreatic sections from non-diabetic human cadaveric donors at different postnatal ages, childhood and adulthood. Pancreatic sections from 1-, 7-, 14- and 28-day-old beta cell-specific Nrf2 (also known as Nfe2l2)-knockout mice (βNrf2KO) or control (Nrf2lox/lox) mice were assessed for beta cell NRF2 levels, beta cell proliferation, beta cell oxidative stress, beta cell death, nuclear beta cell pancreatic duodenal homeobox protein 1 (PDX1) levels and beta cell mass. Seven-day-old βNrf2KO and Nrf2lox/lox mice were injected daily with N-acetylcysteine (NAC) or saline (154 mmol/l NaCl) to explore the potential contribution of oxidative stress to the phenotypes seen in βNrf2KO mice at early postnatal ages. RNA-seq was performed on 7-day-old βNrf2KO and Nrf2lox/lox mice to investigate the mechanisms by which NRF2 stimulates beta cell proliferation at early postnatal ages. Mitochondrial biogenesis and function were determined using dispersed islets from 7-day-old βNrf2KO and Nrf2lox/lox mice by measuring MitoTracker intensity, mtDNA/gDNA ratio and ATP/ADP ratio. To study the effect of neonatal beta cell-specific Nrf2 deletion on glucose homeostasis in adulthood, blood glucose, plasma insulin and insulin secretion were determined and a GTT was performed on 3-month-old βNrf2KO and Nrf2lox/lox mice fed on regular diet (RD) or high-fat diet (HFD). The expression of the master antioxidant regulator NRF2 was increased at early postnatal ages in both human (1 day to 19 months old, 31%) and mouse (7 days old, 57%) beta cells, and gradually declined with age (8% in adult humans, 3.77% in adult mice). A significant correlation (R2=0.568; p=0.001) was found between beta cell proliferation and NRF2 levels in human beta cells. Seven-day-old βNrf2KO mice showed reduced beta cell proliferation (by 65%), beta cell nuclear PDX1 levels (by 23%) and beta cell mass (by 67%), and increased beta cell oxidative stress (threefold) and beta cell death compared with Nrf2lox/lox control mice. NAC injections increased beta cell proliferation in 7-day-old βNrf2KO mice (3.4-fold) compared with saline-injected βNrf2KO mice. Interestingly, RNA-seq of islets isolated from 7-day-old βNrf2KO mice revealed reduced expression of mitochondrial RNA genes and genes involved in the electron transport chain. Islets isolated from 7-day old βNrf2KO mice presented reduced MitoTracker intensity (by 47%), mtDNA/gDNA ratio (by 75%) and ATP/ADP ratio (by 68%) compared with islets from Nrf2lox/lox littermates. Lastly, HFD-fed 3-month-old βNrf2KO male mice displayed a significant reduction in beta cell mass (by 35%), a mild increase in non-fasting blood glucose (1.2-fold), decreased plasma insulin (by 14%), and reduced glucose tolerance (1.3-fold) compared with HFD-fed Nrf2lox/lox mice. Our study highlights NRF2 as an essential transcription factor for maintaining neonatal redox balance, mitochondrial biogenesis and function and beta cell growth, and for preserving functional beta cell mass in adulthood under metabolic stress. Sequencing data are available in the NCBI Gene Expression Omnibus, accession number GSE242718 ( https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE242718 ).

An Analgesic Technique for Orogastric Tube Insertion in Newborns: DOLATSONG, a Randomized Multicentric Controlled Trial.

Gastric tube insertion is necessary to support early enteral feeding of newborns during their neonatal intensive care stay. This frequent and invasive procedure is known to be painful. Very few analgesic techniques (sweet solutions, sucking, swaddling, and skin-to-skin contact) are available to reduce the pain caused by orogastric tube insertion procedure. To determine whether a new orogastric tube insertion technique modifies the pain response in newborns, we hypothesize that inserting an orogastric tube through the nipple of a bottle reduces pain caused by this procedure. Prospective, controlled, randomized, multicentered and open label study. Three neonatal intensive care units in France (2 level 3 units and 1 level 2B). Full-term or premature newborns at 32 weeks of gestation or more, postnatal age between 48 hours and 21 days, not ventilated and requiring enteral feeding, were randomized into 2 groups: usual technique (n = 36) and experimental technique (n = 35). Our experimental technique was to insert the orogastric tube through a modified nipple of a bottle. This method was compared with the usual technique of inserting the tube directly into the newborn's mouth without a support to guide it accompanied by a nipple encouraging sucking with a nonnutritive solution. An association of nonnutritive sucking and orally administered 30% glucose was given to all children for analgesic purposes. Pain during the orogastric tube insertion was assessed on video recordings by 2 independent experts, using a heteroassessment behavioral scale for pain (DAN-Douleur Aiguë du Nouveau-né; APN-Acute Pain in Newborns). The primary outcome was an Acute Pain in Newborns score of less than 3 at the time of the procedure. Comparisons were made using Fisher exact test or Mann-Whitney U test. Factors associated with an Acute Pain in Newborns score of 3 and greater were explored using univariable and multivariable regression models. All but 1 video recording in each group were analyzed. Among the 34 neonates in the experimental group, 71.4% (95% CI: [53.7-85.4]) had an Acute Pain in Newborns score of less than 3 during orogastric tube insertion versus 41% (95% CI: [27.9-61.9]) in the control group (P = .031). Gagging was frequent and nonsignificantly different between the 2 groups (69% in the control group, 51% in the experimental group, P = .13). In multivariable analysis, the experimental technique was an independent factor of pain prevention compared with the usual technique (odds ratio = 0.21 [0.06-0.71], P = .015). This study suggests that a simple, inexpensive, and feasible technique of orogastric tube insertion through the nipple of a bottle limits pain associated with this procedure in newborns.

SOX2 and SOX9 Expression in Developing Postnatal Opossum (Monodelphis domestica) Cortex.

(1) Background: Central nervous system (CNS) development is characterized by dynamic changes in cell proliferation and differentiation. Key regulators of these transitions are the transcription factors such as SOX2 and SOX9. SOX2 is involved in the maintenance of progenitor cell state and neural stem cell multipotency, while SOX9, expressed in neurogenic niches, plays an important role in neuron/glia switch with predominant expression in astrocytes in the adult brain. (2) Methods: To validate SOX2 and SOX9 expression patterns in developing opossum (Monodelphis domestica) cortex, we used immunohistochemistry (IHC) and the isotropic fractionator method on fixed cortical tissue from comparable postnatal ages, as well as dissociated primary neuronal cultures. (3) Results: Neurons positive for both neuronal (TUJ1 or NeuN) and stem cell (SOX2) markers were identified, and their presence was confirmed with all methods and postnatal age groups (P4-6, P6-18, and P30) analyzed. SOX9 showed exclusive staining in non-neuronal cells, and it was coexpressed with SOX2. (4) Conclusions: The persistence of SOX2 expression in developing cortical neurons of M. domestica during the first postnatal month implies the functional role of SOX2 during neuronal differentiation and maturation, which was not previously reported in opossums.

Oscillometry for personalizing continuous distending pressure maneuvers: an observational study in extremely preterm infants

RationaleLung recruitment and continuous distending pressure (CDP) titration are critical for assuring the efficacy of high-frequency ventilation (HFOV) in preterm infants. The limitation of oxygenation (peripheral oxygen saturation, SpO2) in optimizing CDP calls for evaluating other non-invasive bedside measurements. Respiratory reactance (Xrs) at 10 Hz measured by oscillometry reflects lung volume recruitment and tissue strain. In particular, lung volume recruitment and decreased tissue strain result in increased Xrs values.ObjectivesIn extremely preterm infants treated with HFOV as first intention, we aimed to measure the relationship between CDP and Xrs during SpO2-driven CDP optimization.MethodsIn this prospective observational study, extremely preterm infants born before 28 weeks of gestation undergoing SpO2-guided lung recruitment maneuvers were included in the study. SpO2 and Xrs were recorded at each CDP step. The optimal CDP identified by oxygenation (CDPOpt_SpO2) was compared to the CDP providing maximal Xrs on the deflation limb of the recruitment maneuver (CDPXrs).ResultsWe studied 40 infants (gestational age at birth = 22+ 6-27+ 5 wk; postnatal age = 1–23 days). Measurements were well tolerated and provided reliable results in 96% of cases. On average, Xrs decreased during the inflation limb and increased during the deflation limb. Xrs changes were heterogeneous among the infants for the amount of decrease with increasing CDP, the decrease at the lowest CDP of the deflation limb, and the hysteresis of the Xrs vs. CDP curve. In all but five infants, the hysteresis of the Xrs vs. CDP curve suggested effective lung recruitment. CDPOpt_SpO2 and CDPXrs were highly correlated (ρ = 0.71, p < 0.001) and not statistically different (median difference [range] = -1 [-3; 9] cmH2O). However, CDPXrs were equal to CDPOpt_SpO2 in only 6 infants, greater than CDPOpt_SpO2 in 10, and lower in 24 infants.ConclusionsThe Xrs changes described provide complementary information to oxygenation. Further investigation is warranted to refine recruitment maneuvers and CPD settings in preterm infants.

Development and application of neonatal physiology-based pharmacokinetic models of amikacin and fosfomycin to assess pharmacodynamic target attainment.

Antimicrobial resistance increasingly complicates neonatal sepsis in a global context. Fosfomycin and amikacin are two agents being tested in an ongoing multicenter neonatal sepsis trial. Although neonatal pharmacokinetics (PKs) have been described for these drugs, the physiological variability within neonatal populations makes population PKs in this group uncertain. Physiologically-based pharmacokinetic (PBPK) models were developed in Simcyp for fosfomycin and amikacin sequentially for adult, pediatric, and neonatal populations, with visual and quantitative validation compared to observed data at each stage. Simulations were performed using the final validated neonatal models to determine drug exposures for each drug across a demographic range, with probability of target attainment (PTA) assessments. Successfully validated neonatal PBPK models were developed for both fosfomycin and amikacin. PTA analysis demonstrated high probability of target attainment for amikacin 15 mg/kg i.v. q24h and fosfomycin 100 mg/kg (in neonates aged 0-7 days) or 150 mg/kg (in neonates aged 7-28 days) i.v. q12h for Enterobacterales with fosfomycin and amikacin minimum inhibitory concentrations at the adult breakpoints. Repeat analysis in premature populations demonstrated the same result. PTA analysis for a proposed combination fosfomycin-amikacin target was also performed. The simulated regimens, tested in a neonatal sepsis trial, are likely to be adequate for neonates across different postnatal ages and gestational age. This work demonstrates a template for determining target attainment for antimicrobials (alone or in combination) in special populations without sufficient available PK data to otherwise assess with traditional pharmacometric methods.

Modeling Developmental Changes in Caffeine Clearance Considering Differences between Pre- and Postnatal Period.

Taguchi et al. reported that postmenstrual age (PMA) is a promising factor in describing and understanding the developmental change of caffeine (CAF) clearance. The aim of the present study was to quantify how developmental changes occur and to determine the effect of the length of the gestational period on CAF clearance. We performed a nonlinear mixed effect model (NONMEM) analysis and evaluated the fit of six models. A total of 115 samples were obtained from 52 patients with a mean age of 34.3 ± 18.2 d. The median values of gestational age (GA) and postnatal age (PNA) were 196 and 31 d, respectively. Serum CAF levels corrected for dose per body surface area (BSA) (C/D ratioBSA) were dependent on PMA rather than PNA, which supports the findings of a previous study. NONMEM analysis provided the following final model of oral clearance: CL/F = 0.00603∙WT∙<img align="middle" src="./Graphics/abst-math21.png"/>∙0.877GA ≤ 196 L/h. This model takes into account developmental changes during prenatal and postnatal periods separately. The model successfully described the variation in clearance of CAF. Our findings suggest that the dosage of CAF in preterm infants should be determined based not only on body weight (WT) but also on both PNA and GA.

Neurological examination of healthy term infants at ages 6 and 10 weeks in Tshwane District.

Globally, there is a significant gap in detailed neurodevelopmental data for infants under 3 months, despite 6 weeks being identified a critical milestone for neuro-behavioural development. Normative values and optimal scores for healthy infants at 6 and 10 weeks postnatally are lacking in many settings. In South Africa, the statutory neurodevelopmental assessments at these ages exclude notable characteristics of central nervous system maturation and limit opportunities to collect data of early developmental progress. Our study aimed to assess developmental characteristics of healthy term infants aged 6 and 10 weeks using the Hammersmith Neonatal Neurological Examination (HNNE). A prospective longitudinal study was performed on 35 healthy term-born infants from low-risk pregnancies at 6 and 10 weeks' postnatal age in the Tshwane district. The statuses of infants' neurodevelopment in six domains were recorded using the HNNE. Optimality scores were derived from the raw scores of 34 items, using the 10th and 5th percentiles as cut-off points. Evidences of neurodevelopmental advancements, particularly in posture, muscle tone and visual behaviour between 6 and 10 weeks were illustrated, and total examination optimality scores of 29.5 in 91% and 31.5 in 94% of infants were recorded at 6 and 10 weeks, respectively. This article provides data on the neurodevelopment characteristics of infants at and between 6- and 10-weeks post term ages. The findings support the viewpoint to identify important milestone characteristics during early screening.

Staining patterns of PNA and UEA-I lectins in the postnatal developing male genital excurrent duct epithelium in mice.

The research was aimed at determining the staining patterns of Peanut agglutinin (PNA) lectin and Ulex europaeus agglutinin I (UEA-I) lectin in postnatal developing (day 1 to 8 weeks) male genital excurrent duct epithelium in mice. Lectin staining was performed on testis and epididymis of 1-day-old and 1-, 2-, 3-, 4-, 5-, 6-, and 8-week-old ICR mice. Rete testis epithelia were UEA-I- and PNA-negative at all postnatal ages. PNA lectin unclearly stained the epithelial apical surface in efferent ductules (ED) and ductus epididymis up to 2 weeks, while UEA-I was negative in those epithelia. By contrast, at 3 weeks of age, PNA and/or UEA-I turned to clearly label epithelia in the excurrent duct system. At 5 weeks, efferent ductules epithelium was UEA-I-negative but strongly PNA-positive; segment I was PNA-negative but faintly UEA-I positive; segment II was weakly PNA-positive but strongly UEA-I-positive; segment III was strongly-PNA- and UEA-I-positive; segment IV was weakly UEA-I-positive but strongly PNA-positive; and segment V was faintly UEA-I-positive but strongly PNA-positive. At 5 and 8 weeks (the adult), the staining patterns of PNA and UEA-I lectins were nearly identical. Moreover, an increasing staining intensity was observed in both lectins with the advancement of age until 5 weeks of age. Additionally, it was noted that, with the exception of segment I, the staining intensity of PNA gradually increased while that of UEA-I gradually decreased towards the distal section of the ductus epididymis. Lectin PNA and UEA-I staining, in conclusion, indicated epithelial segments in the male genital duct of mice from the postnatal developing age of 3 weeks, and up until 5 weeks, their staining patterns were nearly identical to those in adults.

Neurosonograms in very preterm neonates: Findings, risk factors, and association with neurodevelopmental outcome: A retrospective study

Abstract Background: Neurosonogram (NSG) is a widely used, noninvasive bedside investigation in neonatal intensive care. Yet, actual data on the proportions of abnormal findings, specific conclusions, and its ability to predict outcomes are sparse. We aimed to study these aspects in very preterm infants who are a high-risk group. Materials and Methods: This retrospective descriptive study aimed at analyzing reports of postnatal age-specific NSG reports done in very preterm neonates, and their associations with risk factors. Follow-up information prospectively recorded by the child development services was analyzed for the association of NSG abnormalities with neurodevelopmental impairment (NDI). Results: Clinical and radiological details of 323 very preterm neonates were analyzed. Abnormal NSG (defined as ≥Grade 3 intraventricular hemorrhage/≥Grade 2 periventricular leukomalacia/ventriculomegaly) was reported in 42 infants (13%) at or less than term postmenstrual age; 8% of babies at ≤2 weeks postnatal age; and 12% at 36–40 weeks. Choroid plexus cyst was the most common “other” findings. Gestational age &lt;28 weeks, chorioamnionitis, extensive resuscitation, ventilation &gt;24 h, and culture-proven sepsis were independent risk factors for abnormal NSG in the first 2 weeks of life. Of the babies followed up, 19.25% babies had NDI. The sensitivity of any abnormal NSG was only 16% and the specificity was 91% to predict NDI. The negative predictive value of abnormal NSG for NDI was 79.5%. Conclusion: In very preterm, any abnormal NSG (till term postmenstrual age) was reported in 13% of very preterm. The ability to predict NDI using abnormal NSG reports has a test accuracy of 73.8%.

Lung-Gut Microbiota and Tryptophan Metabolites Changes in Neonatal Acute Respiratory Distress Syndrome.

Neonatal Acute Respiratory Distress Syndrome (NARDS) is a severe respiratory crisis threatening neonatal life. We aim to identify changes in the lung-gut microbiota and lung-plasma tryptophan metabolites in NARDS neonates to provide a differentiated tool and aid in finding potential therapeutic targets. Lower respiratory secretions, faeces and plasma were collected from 50 neonates including 25 NARDS patients (10 patients with mild NARDS in the NARDS_M group and 15 patients with moderate-to-severe NARDS in the NARDS_S group) and 25 control patients screened based on gestational age, postnatal age and birth weight. Lower airway secretions and feces underwent 16S rRNA gene sequencing to understand the microbial communities in the lung and gut, while lower airway secretions and plasma underwent LC-MS analysis to understand tryptophan metabolites in the lung and blood. Correlation analyses were performed by comparing differences in microbiota and tryptophan metabolites between NARDS and control, NARDS_S and NARDS_M groups. Significant changes in lung and gut microbiota as well as lung and plasma tryptophan metabolites were observed in NARDS neonates compared to controls. Proteobacteria and Bacteroidota were increased in the lungs of NARDS neonates, whereas Firmicutes, Streptococcus, and Rothia were reduced. Lactobacillus in the lungs decreased in NARDS_S neonates. Indole-3-carboxaldehyde decreased in the lungs of NARDS neonates, whereas levels of 3-hydroxykynurenine, indoleacetic acid, indolelactic acid, 3-indole propionic acid, indoxyl sulfate, kynurenine, and tryptophan decreased in the lungs of the NARDS_S neonates. Altered microbiota was significantly related to tryptophan metabolites, with changes in lung microbiota and tryptophan metabolites having better differentiated ability for NARDS diagnosis and grading compared to gut and plasma. Significant changes occurred in the lung-gut microbiota and lung-plasma tryptophan metabolites of NARDS neonates. Alterations in lung microbiota and tryptophan metabolites were better discriminatory for the diagnosis and grading of NARDS.