Analysis of the harmonized growth pattern of fetal organs by multidimensional scaling and hierarchical clustering

Assessment of Skin Maturity by LED Light at Birth and Its Association With Lung Maturity: Clinical Trial Secondary Outcomes

BACKGROUND

Clinicians face barriers when assessing lung maturity at birth due to global inequalities. Still, strategies for testing based solely on gestational age to predict the likelihood of respiratory distress syndrome (RDS) do not offer a comprehensive approach to addressing the challenge of uncertain outcomes. We hypothesize that a noninvasive assessment of skin maturity may indicate lung maturity.

OBJECTIVE

This study aimed to assess the association between a newborn's skin maturity and RDS occurrence.

METHODS

We conducted a case-control nested in a prospective cohort study, a secondary endpoint of a multicenter clinical trial. The study was carried out in 5 Brazilian urban reference centers for highly complex perinatal care. Of 781 newborns from the cohort study, 640 were selected for the case-control analysis. Newborns with RDS formed the case group and newborns without RDS were the controls. All newborns with other diseases exhibiting respiratory manifestations were excluded. Skin maturity was assessed from the newborn's skin over the sole by an optical device that acquired a reflection signal through an LED sensor. The device, previously validated, measured and recorded skin reflectance. Clinical data related to respiratory outcomes were gathered from medical records during the 72-hour follow-up of the newborn, or until discharge or death, whichever occurred first. The main outcome measure was the association between skin reflectance and RDS using univariate and multivariate binary logistic regression. Additionally, we assessed the connection between skin reflectance and factors such as neonatal intensive care unit (NICU) admission and the need for ventilatory support.

RESULTS

Out of 604 newborns, 470 (73.4%) were from the RDS group and 170 (26.6%) were from the control group. According to comparisons between the groups, newborns with RDS had a younger gestational age (31.6 vs 39.1 weeks, P<.001) and birth weight (1491 vs 3121 grams, P<.001) than controls. Skin reflectance was associated with RDS (odds ratio [OR] 0.982, 95% CI 0.979-0.985, R2=0.632, P<.001). This relationship remained significant when adjusted by the cofactors antenatal corticosteroid and birth weight (OR 0.994, 95% CI 0.990-0.998, R2=0.843, P<.001). Secondary outcomes also showed differences in skin reflectance. The mean difference was 0.219 (95% CI 0.200-0.238) between newborns that required ventilatory support versus those that did not and 0.223 (95% CI 0.205-0.241) between newborns that required NICU admission versus those that did not. Skin reflectance was associated with ventilatory support (OR 0.996, 95% CI 0.992-0.999, R2=0.814, P=.01) and with NICU admission (OR 0.994, 95% CI 0.990-0.998, R2=0.867, P=.004).

CONCLUSIONS

Our findings present a potential marker of lung immaturity at birth using the indirect method of skin assessment. Using the RDS clinical condition and a medical device, this study demonstrated the synchrony between lung and skin maturity.

TRIAL REGISTRATION

Registro Brasileiro de Ensaios Clínicos (ReBEC) RBR-3f5bm5; https://tinyurl.com/9fb7zrdb.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.1136/bmjopen-2018-027442.

Global pattern of interkinetic nuclear migration in tracheoesophageal epithelia of the mouse embryo: Interorgan and intraorgan regional differences

Interkinetic nuclear migration (INM) is an apicobasal (AB) polarity-based regulatory mechanism of proliferation/differentiation in epithelial stem/progenitor cells. We previously documented INM in the endoderm-derived tracheal/esophageal epithelia at embryonic day (E) 11.5 and suggested that INM is involved in the development of both organs. We here investigated interorgan (trachea vs esophagus) and intraorgan regional (ventral vs dorsal) differences in the INM mode in the tracheal and esophageal epithelia of the mouse embryo. We also analyzed convergent extension (CE) and planar cell movement (PCM) in the epithelia based on cell distribution. The pregnant C57BL/6J mice were intraperitoneally injected with 5-ethynyl-2'-deoxyuridine at E11.5 and E12.5 and were sacrificed 1, 4, 6, 8, and 12 hours later to obtain the embryos. The distribution of labeled cell nuclei along the AB axis was chronologically analyzed in the total, ventral, and dorsal sides of the epithelia. The percentage distribution of the nuclei population was represented by histogram and the chronological change was analyzed statistically using multidimensional scaling. The interorgan comparison of the INM mode during E11.5-E12.0, but not E12.5-E13.0, showed a significant difference. During E11.5-E12.0 the trachea, but not the esophagus, showed a significant difference between ventral and dorsal sides. During E12.5-E13.0 neither organ showed regional differences. CE appeared to occur in both organs during E11.5-E12.0 while PCM was unclear in both organs. These findings suggest a difference between the trachea and esophagus, and a regional difference in the trachea, not in the esophagus, in the INM mode, which may be related with the later differential organogenesis/histogenesis of these organs.

Statistical analysis with dilatation for development process of human fetuses

This paper is concerned with the development process of human fetuses. Though the development process of human fetuses still includes many unknown issues, it is known that a certain harmonious relationship between the organs can be observed. This knowledge is based on our intuition, but we have no theory which clarifies these harmonized developments. The paper aims to give a mathematical understanding of the notion of harmonized development through the use of dilatation, which is a measure of the departure from conformal mapping. The asymptotics for dilatation have been developed using certain efficient models of quasiconformal mapping. The proposed method of dilatation is effectively applied to the human fetus data.

Interkinetic nuclear migration in the mouse embryonic ureteric epithelium: Possible implication for congenital anomalies of the kidney and urinary tract

Interkinetic nuclear migration (INM) is a phenomenon in which progenitor cell nuclei migrate along the apico-basal axis of the pseudostratified epithelium, which is characterized by the presence of apical primary cilia, in synchrony with the cell cycle in a manner of apical mitosis. INM is suggested to regulate not only stem/progenitor cell proliferation/differentiation but also organ size and shape. INM has been reported in epithelia of both ectoderm and endoderm origin. We examined whether INM exists in the mesoderm-derived ureteric epithelium. At embryonic day (E) 11.5, E12.5 and E13.5, C57BL/6J mouse dams were injected with 5-bromo-2'-deoxyuridine (BrdU) and embryos were killed 1, 2, 4, 6, 8, 10 and 12 h later. We immunostained transverse sections of the ureter for BrdU, and measured the position of BrdU (+) nuclei in the ureteric epithelia along the apico-basal axis at each time point. We analyzed the distribution patterns of BrdU (+) nuclei in histograms using the multidimensional scaling. Changes in the nucleus distribution patterns suggested nucleus movement characteristic of INM in the ureteric epithelia, and the mode of INM varied throughout the ureter development. While apical primary cilia are related with INM by providing a centrosome for the apical mitosis, congenital anomalies of the kidney and urinary tract (CAKUT) include syndromes linked to primary ciliary dysfunction affecting epithelial tubular organs such as kidney, ureter, and brain. The present study showed that INM exists in the ureteric epithelium and suggests that INM may be related with the CAKUT etiology via primary ciliary protein function.

Statistical analyses in trials for the comprehensive understanding of organogenesis and histogenesis in humans and mice

Statistical analyses based on the quantitative data from real multicellular organisms are useful as inductive-type studies to analyse complex morphogenetic events in addition to deductive-type analyses using mathematical models. Here, we introduce several of our trials for the statistical analysis of organogenesis and histogenesis of human and mouse embryos and foetuses. Multidimensional scaling has been applied to prove the existence and examine the mode of interkinetic nuclear migration, a regulatory mechanism of stem cell proliferation/differentiation in epithelial tubular tissues. Several statistical methods were used on morphometric data from human foetuses to establish the multidimensional standard growth curve and to describe the relation among the developing organs and body parts. Although the results are still limited, we show that these analyses are not only useful to understand the normal and abnormal morphogenesis in humans and mice but also to provide clues that could correlate aspects of prenatal developmental events with postnatal diseases.

Morphological and morphometric study on sphenoid and basioccipital ossification in normal human fetuses

Congenital anomalies of the brain frequently correspond to cranial base anomalies, and a detailed description of morphology and individual variations in the developing cranial base is of clinical importance for diagnosing anomalies. Development of the human cranial base has been studied using dissection, computed tomography, and magnetic resonance imaging, each of which has advantages and disadvantages. We here examined development of the normal human fetal cranial base using bone staining, which allows for direct observation of the ossification centers and precise three-dimensional measurements. We observed alizarin red S-stained sphenoids and basiocciputs of 22 normal formalin-fixed human fetuses with crown-rump lengths (CRL) of 115-175 mm. We defined landmarks and measured sphenoids and basiocciputs using a fine caliper. Growth patterns of these ossifying bones were obtained, and we found similarities and differences among the growth patterns. We also observed individual variations in the ossification patterns, in particular, single- or double-ossification center patterns for the basisphenoid. The orbitosphenoid and basisphenoid widths and ratios of the widths to the total cranial base width were significantly different between the two pattern groups, whereas the other measurements and their ratios to the total cranial base did not differ between the groups. We measured the cerebrum and pons in different sets of 22 human fetuses with CRLs of 105-186 mm and found close relationships with the development of corresponding parts of the cranial base. The results contribute to the quantitative and qualitative information about the growth patterns and variations during human fetal cranial base development.

Individual variation in organ histogenesis as a causative factor in the developmental origins of health and disease: unnoticed congenital anomalies?

Morphological studies of congenital anomalies have mainly focused on abnormal shape (i.e. malformation) and thus on disturbed organogenesis. However, in regard to postnatal functions of organs that develop through branching mechanisms, organ size is another important morphological feature. These organs consist of a large number of structural and functional units, such as nephrons in the kidney, and the total number of these units, that is approximately proportional to the organ size, has been shown to vary widely among individuals. Organ-specific cells are differentiated and organized to form structural units and realize organ-specific functions during the histogenetic period (i.e. from mid-gestation to the early postnatal period). The total number of units is attained at the end of histogenesis and determines the total functional capacity, including the functional reserve of the organ, and thus may be related to predispositions to postnatal organ-based diseases, because the functional reserve decreases during the course of life and eventually become short of the minimum requirement of each organ. Therefore, it may be hypothesized that a smaller number of units of organs at the end of histogenesis is one of the predisposing factors for postnatal diseases (i.e. a form of unnoticed but late-manifested congenital anomalies), in this era of extended longevity. However, the mechanisms that control the total number of units in each organ during histogenesis and the possible relationship among the numbers of units in different organs remain unknown. Here, we review our trials based on the above hypothesis in order to (1) mathematically analyze the morphometric data of the different organs in fetuses to elucidate relationship among developing organs, (2) analyze the developing neuro-immuno-endocrine network as a series of mechanisms to systemically correlate the histogenesis of multiple organs, and (3) examine the maternal environment, including dietary fat, as a factor to influence histogenesis and thus the predisposition to type 1 diabetes.