A novel site of haematopoiesis and appearance and dispersal of distinct haemocyte types in the Manduca sexta embryo (Insecta, Lepidoptera).

With a set of haemocyte specific markers novel findings on haematopoiesis in the Manduca sexta embryo are presented. We identify a hitherto unknown paired haematopoietic cluster, the abdominal haemocyte cluster in abdominal segment 7 (A7-HCC). These clusters are localised at distinct positions and are established at around katatrepsis. Later in embryogenesis, the A7-HCCs disintegrate, thereby releasing numerous embryonic plasmatocytes which disperse both anteriorly and posteriorly. These cells follow stereotypic migration routes projecting anteriorly. The thoracic larval haematopoietic organs are established at around midembryogenesis. We identify embryonic oenocytoids in the M. sexta embryo for the first time. They appear in the head region roughly at the same time as the A7-HCCs occur and successively disperse in the body cavity during development. Localisation of the prophenoloxidase (proPO) mRNA and of the proPO protein are identical. Morphological, cytometric and antigenic traits show three independently generated haemocyte types during embryogenesis.

Differences in cardiac geometry in relation to body size among neonates with abnormal prenatal growth and body size at birth.

OBJECTIVES: Both excessive and restricted fetal growth are associated with changes in cardiac geometry and function at birth. There are significant issues when indexing cardiac parameters for body size in the neonatal period. The aims of this study were to determine to what extent cardiac geometry is dependent on body size in term and preterm neonates with restricted or excessive fetal growth and how this is affected by adiposity. METHODS: This was a cross-sectional study of neonates born between 31 and 42 weeks of gestation, divided into three groups: (1) small-for-gestational age (SGA, birth weight > 2 SD below the mean); (2) large-for-gestational age (LGA, birth weight > 2 SD above the mean); and (3) appropriate-for-gestational-age controls (AGA, birth weight ≤ 2 SD from the mean). Cardiac geometry and function were compared between the study groups, adjusting for body size. The potential impact of infant adiposity and maternal disease was assessed. RESULTS: In total, 174 neonates were included, of which 39 were SGA, 45 were LGA and 90 were AGA. Body size was reflected in cardiac dimensions, with differences in cardiac dimensions disappearing between the SGA and AGA groups when indexed for body surface area (BSA) or thoracic circumference. The same was true for the differences in atrial and ventricular areas between the LGA and AGA groups. However, left ventricular inflow and outflow tract dimensions did not follow this trend as, when indexed for BSA, they were associated negatively with adiposity, resulting in diminished dimensions in LGA compared with AGA and SGA neonates. Adiposity was associated positively with left ventricular mass, right ventricular length and area and right atrial area. The SGA group showed increased right ventricular fractional area change, possibly reflecting differences in the systolic function of the right ventricle. We found evidence of altered diastolic function between the groups, with the mitral valve inflow E- to lateral E'-wave peak velocity ratio being increased in the LGA group and decreased in the SGA group. CONCLUSIONS: Cardiac geometry is explained by body size in both term and preterm AGA and SGA infants. However, the nature of the relationship between body size and cardiac dimensions may be influenced by adiposity in LGA infants, leading to underestimation of left ventricular inflow and outflow tract dimensions when adjusted for BSA. Adjustments for thoracic circumference provide similar results to those for BSA. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Non-apoptotic function of Drosophila caspase activation in epithelial thorax closure and wound healing.

Non-apoptotic caspase activation involves multiple cellular events. However, the link between visible non-apoptotic caspase activation and its function in living organisms has not yet been revealed. Here, we visualized sub-lethal activation of apoptotic signaling with the combination of a sensitive indicator for caspase 3 activation and in vivo live-imaging analysis of Drosophila During thorax closure in pupal development, caspase 3 activation was specifically observed at the leading edge cells, with no signs of apoptosis. Inhibition of caspase activation led to an increase in thorax closing speed, which suggests a role of non-apoptotic caspase activity in cell motility. Importantly, sub-lethal activation of caspase 3 was also observed during wound closure at the fusion sites at which thorax closure had previously taken place. Further genetic analysis revealed that the activation of the initiator caspase Dronc is coupled with the generation of reactive oxygen species. The activation of Dronc also regulates myosin levels and delays wound healing. Our findings suggest a possible function for non-apoptotic caspase activation in the fine-tuning of cell migratory behavior during epithelial closure.

Reproducibility of Liver-to-Thorax Area Ratio Ultrasound Measurements in Congenital Diaphragmatic Hernia.

OBJECTIVES: The aim of this study was to investigate the reproducibility of a standardized method to assess the ultrasound liver-to-thoracic area ratio in fetuses with congenital diaphragmatic hernia. METHODS: We selected 24 images of 9 fetuses diagnosed with left-sided at our institution between January 2010 and December 2017. Eight operators (1 maternal-fetal medicine specialist and 7 sonographers) reviewed the selected images and assessed the ultrasound liver-to-thoracic area ratio according to a standardized protocol. We evaluated the correlation between operators using the intraclass correlation coefficient and compared agreement between the sonographers and a physician with experience in measuring the ultrasound liver-to-thoracic area ratio using a Bland-Altman analysis. RESULTS: Good intraoperator reproducibility was observed for the standardized ultrasound liver-to-thoracic area ratio (intraclass correlation coefficient, 0.78). Good agreement among sonographers and the physician was also observed for the standardized measurements (bias, 0.01; precision, 0.03; limits of agreement, -0.05 to + 0.07). CONCLUSIONS: We demonstrated that good intraoperator and interoperator reproducibility of ultrasound liver-to-thoracic area ratio assessment is feasible after standardizing the method in our center.

Gene expression patterns determine the differential numbers of dorsocentral macrochaetes between Musca domestica and Drosophila melanogaster.

The evolutionary differences in sensory bristle patterns on the thorax of dipterans are an excellent model for studying the patterns of evolutionary development. We observed that Drosophila melanogaster has two pairs of the large bristles, called macrochaetes, in the dorsocentral (DC) region of the notum, while Musca domestica retains six DC macrochaetes. To explore possible mechanism by which these two dipteran species have different numbers of DC bristles, we compared the corresponding protein sequences, the gene expression levels and the spatial expression patterns of five genes (scute, pnr, ush, hairy, and emc) for bristle development between two species. We also checked the overexpression of scute and emc in transgenic flies. The results demonstrated a strong conservation of five protein sequences between these two species. The mRNA expression of the five genes differed significantly between D. melanogaster and M. domestica. The gene expression patterns exhibited a species-specific pattern during the larval development stage. It suggests that the function of these genes has been conserved in regulating the development of macrocheates between housefly and fruit fly, whereas the gene expression levels, especially spatial expression patterns lead to species-specificity in DC bristles.

High expression of A-type lamin in the leading front is required for Drosophila thorax closure.

Tissue closure involves the coordinated unidirectional movement of a group of cells without loss of cell-cell contact. However, the molecular mechanisms controlling the tissue closure are not fully understood. Here, we demonstrate that Lamin C, the sole A-type lamin in Drosophila, contributes to the process of thorax closure in pupa. High expression of Lamin C was observed at the leading front of the migrating wing imaginal discs. Live imaging analysis revealed that knockdown of Lamin C in the thorax region affected the coordinated movement of the leading front, resulting in incomplete tissue fusion required for formation of the adult thorax. The closure defect due to knockdown of Lamin C correlated with insufficient accumulation of F-actin at the front. Our study indicates a link between A-type lamin and the cell migration behavior during tissue closure.

[Fetal MRI practices in a university prenatal center]. / Pratique de l'IRM fœtale dans un centre hospitalo-universitaire de diagnostic prénatal.

OBJECTIVES: Fetal MRI is a third intention examination to prenatal diagnosis. If its diagnostic value is well known in many pathologies, its place in the management of pregnancies remains unclear. METHODS: We collected retrospectively demographical, radiological (fetal MRI indications, fetal anatomical region and diagnostic information provided by fetal MRI) and obstetrical data of pregnant patients in university prenatal center during a 5 years' period. RESULTS: Among 2439 patients of the prenatal center, 196 (8%) patients with fetal MRI were included. The main anatomical regions studied were the brain (n=132, 67%), the thorax (n=31, 16%) and the abdomen (n=25, 13%). No cardiac fetal MRI was performed. Ninety-five percent of fetal MRI was consecutively of an ultrasound sign. Fetal brain MRI was abnormal in 65% of cases, the thoracic and abdominopelvic MRI in 81.5%. The ultrasound diagnosis was unchanged in 42%, completed in 50% and redirected in 8% of cases. A termination of pregnancy was deemed admissible in 31% of patients with MRI versus 21% in patients without MRI (P=0.001). CONCLUSION: Fetal MRI requires selective indications and provides additional diagnostic information with important implications for the future of the pregnancy, particularly in case of severe and incurable pathologies. Our results could be useful as a reference basis for the comparison with others prenatal center practices.

Myc inhibits JNK-mediated cell death in vivo.

The proto-oncogene Myc is well known for its roles in promoting cell growth, proliferation and apoptosis. However, in this study, we found from a genetic screen that Myc inhibits, rather than promotes, cell death triggered by c-Jun N-terminal kinase (JNK) signaling in Drosophila. Firstly, expression of Drosophila Myc (dMyc) suppresses, whereas loss of dMyc enhances, ectopically activated JNK signaling-induced cell death. Secondly, dMyc impedes physiologically activated JNK pathway-mediated cell death. Thirdly, loss of dMyc triggers JNK pathway activation and JNK-dependent cell death. Finally, the mammalian cMyc gene, when expressed in Drosophila, impedes activated JNK signaling-induced cell death. Thus, besides its well-studied apoptosis promoting function, Myc also antagonizes JNK-mediated cell death in Drosophila, and this function is likely conserved from fly to human.

Drosophila FoxL1 non-autonomously coordinates organ placement during embryonic development.

Determining how organs attain precise positioning within an organism is a crucial facet of developmental biology. The Fox family winged-helix transcription factors are known to play key roles in development of multiple organs. Drosophila FoxL1 (aka Fd64A) is dynamically expressed in embryos but its function is completely uncharacterized. FoxL1 is expressed in a single group of body wall - muscles in the 2nd and 3rd thoracic segments, in homologous abdominal muscles at earlier stages, and in the hindgut mesoderm from early through late embryogenesis. We show that FoxL1 expression in T2 and T3 is in VIS5, which is not a single muscle spanning the entire thorax, as previously published, but is, instead, three individual muscles, each spanning a single thoracic segment. We generate mutations in foxL1 and show that, surprisingly, none of the tissues that express FoxL1 are affected by its loss. Instead, loss of foxL1 results in defects in salivary gland positioning and morphology, as well as defects in the migration of hemocytes, germ cells and Malpighian tubules. We also show that FoxL1-dependent expression of secreted Sema2a in T3 VIS5 is required for normal salivary gland positioning. Altogether, these findings suggest that Drosophila FoxL1 functions like its mammalian counterpart in non-autonomously orchestrating the behaviors of surrounding tissues.

Gene expression profiles uncover individual identities of gnathal neuroblasts and serial homologies in the embryonic CNS of Drosophila.

The numbers and types of progeny cells generated by neural stem cells in the developing CNS are adapted to its region-specific functional requirements. In Drosophila, segmental units of the CNS develop from well-defined patterns of neuroblasts. Here we constructed comprehensive neuroblast maps for the three gnathal head segments. Based on the spatiotemporal pattern of neuroblast formation and the expression profiles of 46 marker genes (41 transcription factors), each neuroblast can be uniquely identified. Compared with the thoracic ground state, neuroblast numbers are progressively reduced in labial, maxillary and mandibular segments due to smaller sizes of neuroectodermal anlagen and, partially, to suppression of neuroblast formation and induction of programmed cell death by the Hox gene Deformed Neuroblast patterns are further influenced by segmental modifications in dorsoventral and proneural gene expression. With the previously published neuroblast maps and those presented here for the gnathal region, all neuroectodermal neuroblasts building the CNS of the fly (ventral nerve cord and brain, except optic lobes) are now individually identified (in total 2×567 neuroblasts). This allows, for the first time, a comparison of the characteristics of segmental populations of stem cells and to screen for serially homologous neuroblasts throughout the CNS. We show that approximately half of the deutocerebral and all of the tritocerebral (posterior brain) and gnathal neuroblasts, but none of the protocerebral (anterior brain) neuroblasts, display serial homology to neuroblasts in thoracic/abdominal neuromeres. Modifications in the molecular signature of serially homologous neuroblasts are likely to determine the segment-specific characteristics of their lineages.

Drosophila 4EHP is essential for the larval-pupal transition and required in the prothoracic gland for ecdysone biosynthesis.

Maternal expression of the translational regulator 4EHP (eIF4E-Homologous Protein) has an established role in generating protein gradients essential for specifying the Drosophila embryonic pattern. We generated a null mutation of 4EHP, which revealed for the first time that it is essential for viability and for completion of development. In fact, 4EHP null larvae, and larvae ubiquitously expressing RNAi targeting 4EHP, are developmentally delayed, fail to grow and eventually die. In addition, we found that expressing RNAi that targets 4EHP specifically in the prothoracic gland disrupted ecdysone biosynthesis, causing a block of the transition from the larval to pupal stages. This phenotype can be rescued by dietary administration of ecdysone. Consistent with this, 4EHP is highly expressed in the prothoracic gland and it is required for wild type expression levels of steroidogenic enzymes. Taken together, these results uncover a novel essential function for 4EHP in regulating ecdysone biosynthesis.

Comprehensive analysis of Hox gene expression in the amphipod crustacean Parhyale hawaiensis.

Hox genes play crucial roles in establishing regional identity along the anterior-posterior axis in bilaterian animals, and have been implicated in generating morphological diversity throughout evolution. Here we report the identification, expression, and initial genomic characterization of the complete set of Hox genes from the amphipod crustacean Parhyale hawaiensis. Parhyale is an emerging model system that is amenable to experimental manipulations and evolutionary comparisons among the arthropods. Our analyses indicate that the Parhyale genome contains a single copy of each canonical Hox gene with the exception of fushi tarazu, and preliminary mapping suggests that at least some of these genes are clustered together in the genome. With few exceptions, Parhyale Hox genes exhibit both temporal and spatial colinearity, and expression boundaries correlate with morphological differences between segments and their associated appendages. This work represents the most comprehensive analysis of Hox gene expression in a crustacean to date, and provides a foundation for functional studies aimed at elucidating the role of Hox genes in arthropod development and evolution.

Notch signaling induces cell proliferation in the labrum in a regulatory network different from the thoracic legs.

The insect head is composed of several segments and an anterior non-segmental region. While patterning of the segmental region relies - at least in part - on the known trunk patterning mechanisms, development of the anterior most region remains poorly understood. The labrum is an enigmatic structure of the anterior median region (AMR) of the insect head. Based on similar development and gene expression patterns it has been suggested to be a serial homolog of trunk appendages. However, its position in the non-segmental region indicated an independent origin. In order to learn more about development of the AMR including the labrum, we screened the results of the large scale RNAi screen iBeetle to identify novel genes. We found the Notch ligand Tc-Serrate and the ubiquitin ligase Tc-mind bomb1 to be required for labrum formation. Further studies showed that Notch signaling is acting upstream of the genetic hierarchy and is required for regulating cell proliferation. We combined our work with previous data to compare the regulatory gene networks of labrum and trunk appendage formation. This reveals that despite the involvement of a similar set of genes, the genetic interactions are quite different.

Case Report: Fetal Bilateral Diaphragmatic Agenesis, Ectopic Liver and Abnormal Pancreas.

Congenital bilateral diaphragm agenesis is a very rare condition. We describe limited (abdomen only) autopsy findings of a case of bilateral diaphragm agenesis in a 27-week male fetus with unusual findings of fibrosis of the pancreatic head and ectopic liver nodules in a mass at the upper abdomen that may represent a possible diaphragm anlage. We have correlated our observations with data from experimental and embryological studies to suggest possible mechanisms for the malformations that were present and their implications for our understanding of pancreas, liver and diaphragm development in the human fetus.

Motion corrected 3D reconstruction of the fetal thorax from prenatal MRI.

In this paper we present a semi-automatic method for analysis of the fetal thorax in genuine three-dimensional volumes. After one initial click we localize the spine and accurately determine the volume of the fetal lung from high resolution volumetric images reconstructed from motion corrupted prenatal Magnetic Resonance Imaging (MRI). We compare the current state-of-the-art method of segmenting the lung in a slice-by-slice manner with the most recent multi-scan reconstruction methods. We use fast rotation invariant spherical harmonics image descriptors with Classification Forest ensemble learning methods to extract the spinal cord and show an efficient way to generate a segmentation prior for the fetal lung from this information for two different MRI field strengths. The spinal cord can be segmented with a DICE coefficient of 0.89 and the automatic lung segmentation has been evaluated with a DICE coefficient of 0.87. We evaluate our method on 29 fetuses with a gestational age (GA) between 20 and 38 weeks and show that our computed segmentations and the manual ground truth correlate well with the recorded values in literature.

The clavicular part of the pectoralis major: a true entity of the upper limb on anatomical, phylogenetic, ontogenetic, functional and clinical bases. Case report and review of the literature.

The pectoralis major consists of three parts: clavicular, sternocostal and abdominal. The first is usually separated from the deltoid by a deltopectoral triangular space, and often from the sternocostal part by another triangular space. The clavicular part is a new acquisition in Anthropoids, to optimize stabilization of the upper limb to the thorax thus permitting an increased limb mobility in Primates. It is synergetic with the deltoid in arm flexion and even more in adduction. This action is important in Humans, as the coracobrachialis becomes smaller in Mammals. Among non human Primates, those having cranially displaced shoulder joint show a significant clavicular origin of the pectoralis major. The clavicular origin might be necessary in flexion of the forelimb, when the humeral insertion of the muscle is on the same transverse plane as, or cranial to, the sternal manubrium. As to the blood and nerve supply, occurrence in Humans of a neuro-vascular pedicle for the clavicular part, shared with the deltoid, indicates a relatively morpho-functional independence of this part from the rest of the muscle. Under this regard, the width of the lateral pectoral nerve, which supplies the clavicular part of the muscle, may be related to a greater functional ability. Many manoeuvres for plastic and reconstructive surgery are performed by isolating the clavicular part of the pectoralis major. Indeed, this part may be considered as a true, self-standing anatomical entity. In fact, it has morphological individuality, peculiar bony attachments and functional autonomy, so that it is simply adjacent to the sternocostal part. Moreover, according to phylogenesis, this topographic relation develops secondarily, in parallel with the development of the clavicle. Therefore, it may be regarded not only as a simple part of an extrinsic muscle of the thorax, but also as an intrinsic muscle of the upper limb.

Prenatal prediction of neonatal survival in cases diagnosed with congenital diaphragmatic hernia using abdomen-to-thorax ratio determined by ultrasonography.

AIM: The aim of this study was to evaluate the usefulness of abdomen-to-thorax ratio (ATR) measured by antenatal ultrasonography for predicting neonatal survival of fetuses with congenital diaphragmatic hernia (CDH). MATERIAL AND METHODS: We identified 75 fetuses who were prenatally diagnosed with CDH and delivered in Seoul National University Hospital from 1998 to 2012, retrospectively. Of these, 40 cases who met the following criteria were included: (i) singleton pregnancy; (ii) a case that had available ultrasonographic images; and (iii) a neonate in whom follow-up until discharge from the hospital was available. ATR was measured as follows: each anteroposterior distance (APD) in the abdominal and thoracic cavity was measured in the same midsagittal plane with the fetal neutral position. A thoracic APD was measured from the back to the distal end of the sternum and an abdominal APD from the back to the most protruding abdominal surface. ATR is the ratio of the abdominal APD versus the thoracic APD. RESULTS: Survival rates were 57.5%. There were significant differences in ATR, lung-head ratio (LHR), observed/expected-LHR, quantitative lung index and intrathoracic liver between survivors and non-survivors. Regression analysis demonstrated that only ATR and intrathoracic position of the liver were independent predictors of survival. ATR by multivariate analysis had the most influence on survival rate (P = 0.002). The area under the receiver-operator curve for prediction of survival from ATR was 0.770 (P = 0.004). The diagnostic cut-off value for ATR was 0.96. CONCLUSIONS: Because ATR is effective to predict neonatal survival in CDH fetuses and is easy to measure, it can be used as another powerful parameter for managing CDH fetuses.

Congenital agminated segmental nevi of the chest.

Grouped patterns of pigmented lesions are infrequent. Of the several reports of agminated nevi, most have been Spitz nevi or blue nevi. The distribution of these nevi is often segmental, following a dermatome or the lines of Blaschko. Most segmental nevi are not agminated and develop early in childhood [1]. We describe a rare case of congenital agminated segmental nevi on the chest.

Prenatal development of the fetal thoracic sympathetic trunk in sheep (Ovis aries).

This study aims at clarifying the detailed morphological and topographical changes of the thoracic part of the sympathetic trunk of sheep during fetal development. Bilateral micro-dissection of the thoracic sympathetic trunk was performed on 40 sheep fetuses aged 6-20 weeks (18 males and 22 females) under a stereomicroscope. The cervicothoracic ganglion (CTG) was observed on 75/80 sides (93.7%) and was composed of the caudal cervical and the first thoracic ganglia on 45/80 sides (56.2%), and of the caudal cervical and the first two thoracic ganglia on 30/80 sides (37.5%). The presence of the two last (12th-13th) thoracic ganglia was not constant. The influence of the sex, the side of the body, and the ages of the fetus on the morphology and topography of the thoracic sympathetic trunk in sheep were identified. In spite of the differences in the morphology and topography of the thoracic sympathetic trunk between early and late fetal developments, the morphology and topography of the older fetal thoracic sympathetic trunk tended to be similar to that of the adult sheep. To comprehend the comparative morphology of the fetal thoracic sympathetic trunk more completely, our results were compared with previous studies. Consequently, differences and similarities in the composition and position of the CTG, presence of single caudal cervical ganglion without fusion to the thoracic ganglia, and absence of the thoracic ganglia, and presence of splitting of the interganglionic branch were found among sheep, pig, and human fetuses. Therefore, sheep might be the appropriate animal model to be applied in human sympathetic nervous system.