Fetal Research Articles

Human erythroid progenitors express antigen presentation machinery.

Early-life immune exposures can profoundly impact lifelong health. However, functional mechanisms underlying fetal immune development remain incomplete. Erythrocytes are not typically considered active immune mediators, primarily because erythroid precursors discard their organelles as they mature, thus losing the ability to alter gene expression in response to stimuli. Erythroid progenitors and precursors circulate in human fetuses and neonates. Although there is limited evidence that erythroid precursors are immunomodulatory, our understanding of the underlying mechanisms remains inadequate. To define the immunobiological role of fetal and perinatal erythroid progenitors and precursors, we analyzed single cell RNA-sequencing data and found that transcriptomics support erythroid progenitors as putative immune mediators. Unexpectedly, we discovered that human erythroid progenitors constitutively express Major Histocompatibility Complex (MHC) class II antigen processing and presentation machinery, which are hallmarks of specialized antigen presenting immune cells. Furthermore, we demonstrate that erythroid progenitors internalize and cleave foreign proteins into peptide antigens. Unlike conventional antigen presenting cells, erythroid progenitors express atypical costimulatory molecules and immunoregulatory cytokines that direct the development of regulatory T cells, which are critical for establishing maternal-fetal tolerance. Expression of MHC II in definitive erythroid progenitors begins during the second trimester, coinciding with the appearance of mature T cells in the fetus, and is absent in primitive progenitors. Lastly, we demonstrate physical and molecular interaction potential of erythroid progenitors and T cells in the fetal liver. Our findings shed light on a unique orchestrator of fetal immunity and provide insight into the mechanisms by which erythroid cells contribute to host defense.

Effects of valproic acid on transcript levels in neurotrophin signaling pathway in mice hippocampus according to the implementation period

Abstract Background/Aim Valproic acid (VPA), is an antiepileptic drug and it has been known for a long time that exposure to VPA in the fetal period causes many behavioral, cognitive, and structural disorders. In this study, we aimed to evaluate the effects of the implementation period of VPA during pregnancy on both behavioral tests and the expression of 45 key genes belonging to the neurotrophin signaling pathway. Methods The study was designed to form four different groups of five female mice in each group. The experimental and control groups were divided into mature (n = 5) and immature (n = 5) subgroups, respectively. VPA (500 mg/kg dose) was subcutaneously administered to the experimental groups. All mice were first tested for behavioral changes, and then the hippo-campal tissues were used for RNA isolation. The expression levels of 45 transcripts associated with the neurotrophin signaling pathway were determined by real-time RT-PCR in the hippocampus. Results No differences were found between the groups in any of the behavioral tests. When gene expression was examined, there was a difference between the groups in the transcript levels of Ngf(neurotrophic growth factor), Ntrk2 (neurotrophic receptor tyrosine kinase 2), Shc1 (SHC adaptor protein 1), Chka (choline kinase alpha), and Mapk1 (mitogen-activated protein kinase 1) genes. Conclusions This study demonstrated the effects of VPA on transcript levels at different maturation stages. We believe that it is important to explain the structural and cognitive teratogenic side effects caused by VPA in human fetuses using genes whose expression changes.

The brain of fetuses with congenital diaphragmatic hernia shows signs of hypoxic injury with loss of progenitor cells, neurons, and oligodendrocytes

Congenital diaphragmatic hernia (CDH) is a birth defect characterized by incomplete closure of the diaphragm, herniation of abdominal organs into the chest, and compression of the lungs and the heart. Besides complications related to pulmonary hypoplasia, 1 in 4 survivors develop neurodevelopmental impairment, whose etiology remains unclear. Using a fetal rat model of CDH, we demonstrated that the compression exerted by herniated organs on the mediastinal structures results in decreased brain perfusion on ultrafast ultrasound, cerebral hypoxia with compensatory angiogenesis, mature neuron and oligodendrocyte loss, and activated microglia. In CDH fetuses, apoptosis was prominent in the subventricular and subgranular zones, areas that are key for neurogenesis. We validated these findings in the autopsy samples of four human fetuses with CDH compared to age- and sex-matched controls. This study reveals the molecular mechanisms and cellular changes that occur in the brain of fetuses with CDH and creates opportunities for therapeutic targets.

Quantitative study of the ossification centers of the body of sphenoid bone in the human fetus

The aim of the present study was to examine the growth dynamics of the two ossification centers of the body of sphenoid bone in the human fetus, based on their linear, planar and volumetric parameters. The examinations were carried out on 37 human fetuses of both sexes aged 18–30 weeks of gestation, which had been preserved in 10% neutral formalin solution. Using CT, digital image analysis software, 3D reconstruction and statistical methods, we evaluated the size of the presphenoid and postsphenoid ossification centers. The presphenoid ossification center grew proportionately in sagittal diameter, projection surface area and volume, and logarithmically in transverse diameter. The postsphenoid ossification center increased logarithmically in sagittal diameter, transverse diameter and projection surface area, while its volumetric growth followed proportionately. The numerical findings of the presphenoid and postsphenoid ossification centers may be considered age-specific reference values of potential relevance in monitoring the normal fetal growth and screening for congenital disorders in the fetus. The obtained results may contribute to a better understanding of the growing fetal skeleton, bringing new numerical information regarding its diagnosis and development.

A FABULOUS WORLD

“Um mundo fabuloso” (“A Fabulous World”) is one of Flusser’s earliest articles, published on November 28, 1964, in the literary supplement of the newspaper O Estado de S. Paulo. In it, with exact fantasy, an octopus, a tapeworm, and a human fetus address the reader on their superiority over the others, exploring the friction between Darwinian and Freudian theories. If Flusser resorts to the tradition of the fable, it is only to point to the fact that we cannot go back to the times of La Fontaine or those even more primitive times of cavemen and their hunt stories around the bonfires, for the fables of our times are scientific. The essay can be considered seminal because in it Flusser already plays with the characteristic perspectivism of his philosophical fiction, and because later the philosopher will dedicate individual texts to each of the three animals. The octopus will be the main subject of Vampyroteuthis infernalis (FLUSSER; BEC, 2011), in which Flusser claimed to have done “fictional science”, and the others turn into protagonists of two of the “scenarios for the future” from Angenommen, or What If? (FLUSSER, 2022).

Development of the Fetal Brain Corticocortical Structural Network during the Second-to-Third Trimester Based on Diffusion MRI.

During the second-to-third trimester, the neuronal pathways of the fetal brain experience rapid development, resulting in the complex architecture of the interwired network at birth. While diffusion MRI-based tractography has been employed to study the prenatal development of structural connectivity network (SCN) in preterm neonatal and postmortem fetal brains, the in utero development of SCN in the normal fetal brain remains largely unknown. In this study, we utilized in utero dMRI data from human fetuses of both sexes between 26 and 38 gestational weeks to investigate the developmental trajectories of the fetal brain SCN, focusing on intrahemispheric connections. Our analysis revealed significant increases in global efficiency, mean local efficiency, and clustering coefficient, along with significant decrease in shortest path length, while small-worldness persisted during the studied period, revealing balanced network integration and segregation. Widespread short-ranged connectivity strengthened significantly. The nodal strength developed in a posterior-to-anterior and medial-to-lateral order, reflecting a spatiotemporal gradient in cortical network connectivity development. Moreover, we observed distinct lateralization patterns in the fetal brain SCN. Globally, there was a leftward lateralization in network efficiency, clustering coefficient, and small-worldness. The regional lateralization patterns in most language, motor, and visual-related areas were consistent with prior knowledge, except for Wernicke's area, indicating lateralized brain wiring is an innate property of the human brain starting from the fetal period. Our findings provided a comprehensive view of the development of the fetal brain SCN and its lateralization, as a normative template that may be used to characterize atypical development.

Morphological features of the pons in human fetuses 14-15 weeks of intrauterine development

Knowledge of human embryonic development is essential to improve our understanding of human fetal anatomy and for better understanding the etiology of congenital malformations. Currently, the structures of the posterior cranial fossa and the brain stem are of great interest to researchers, because of a large number of nuclei are located in the pons area, which play an important role in ensuring vital functions. The aim of the scientific work is to establish the morphological features of the pons of human fetuses at 14-15 weeks of gestation, the size and area of the nuclei of cranial nerves and neurons which are located in the area of the pons. Anatomical and histological research was carried out on 6 human fetuses aged 14-15 weeks of gestation. The cadaver material for research was obtained as a result of late abortions which were conducted according to medical indications in Vinnytsia maternity hospitals. Preparations were fixed in a 10 % solution of neutral formalin, stained with hematoxylin-eosin, toluidine blue modified by Nissl. Computer histometry (Toup View) was used for morphometric research. Statistical digital data were processed on a personal computer using Microsoft Excel 2016 and “Statistica 6.1” software. We established that in human fetuses at 14-15 weeks of intrauterine development, the nuclei of the trigeminal, abductor and vestibulocochlear nerves were detected. The nucleus of the facial nerve on 14-15 weeks of gestation is represented by single polygonal nerve cells with eosinophilic cytoplasm. The nucleus of the abductor nerve had the largest area, the cochlear nucleus of the vestibulocochlear nerve had the smallest area. The largest area of neurons was in the nuclei of the VIII pair of cranial nerve, the smallest – in the nucleus of the abductor and facial nerves. At 14-15 weeks of intrauterine development of human fetuses, the area of the cell nucleus could be determined only in the nuclei of the vestibulocochlear nerve, while the cell nuclei of the trigeminal, facial, and abductor nerves were represented by nerve cells of a spherical shape with a nucleus in which a basophilic nucleolus and a homogeneous eosinophilic cytoplasm were noted. Thus, in human fetuses of 14-15 weeks of intrauterine development, differences in the sizes and areas of the nuclei of cranial nerves and neurons that form nuclei in the pons area were found.

Fetal ultrasound anatomy and morphometric parameters of the tibia

Ultrasound screening is one of the most informative methods of visualizing fetal development during pregnancy. During standard ultrasound examinations, the length of the femur of the fetus is measured. However, if any skeletal dysplasia or intrauterine growth retardation is suspected, additional measurement of other long tubular bones should be performed. The aim of the work was to investigate the morphometric parameters of the lengths of the right and left tibia bones and to establish correlations between them and the lengths of the corresponding fibula, lower limb and crown rump length of the fetus during the fetal period of human ontogenesis. Intravital ultrasound examination of the leg bones of 38 human fetuses was performed at the medical center "YUZKO MEDICAL CENTER" in accordance with the cooperation agreement. Built-in capabilities of MS Excel were used for statistical calculations. The established data on the fetal morphometry of tibial lengths indicate relatively uniform growth of the right and left tibias during the fetal period of human ontogenesis: the length of the right tibia increases from 24.77±2.25 mm to 65.32±2.20 mm, and the length of the left tibia increases from 25.19±1.63 mm to 65.78±1.81 mm. The analysis of correlations between the length of the right and left tibia bones, the length of the fibula bones, the length of the lower limbs and the crown rump length in human fetuses aged from 4 to 10 months of intrauterine development allowed to reveal reliable strong and medium strength reliable and unreliable, mostly direct, connections in all age groups. The obtained morphometric parameters of tibia bones in fetuses of different gestational periods are important additional dimensions of fetobiometry, which can be used if a detailed assessment of the state of fetal development is necessary and in case of suspicion of congenital anomalies.

Population Atlas Analysis of Emerging Brain Structural Connections in the Human Fetus

Population Atlas Analysis of Emerging Brain Structural Connections in the Human Fetus

Histological Observations of the Developing Human Fetal Humerus at Different Trimesters of Pregnancy

Background: Although femur length is the preferred method for fetal age assessment, the humerus is sometimes the right choice, especially in the second half of pregnancy. Fetal bone development significantly impacts adult bone quality and senescent bone disorders, including osteoporosis. Purpose of the study: The present study aimed to ascertain the histological changes in the human fetal humerus across the three trimesters. After the institutional ethical committee clearance and parent consent, the study was carried out on stillborn or medically terminated human fetuses from the 10th to the 32nd week of intrauterine life. Results: First trimester: The primary bone collar appeared with the primary ossification center, marked by more vascular invasion and a pool of mesenchymal cells. Trabeculations begin from the bony collar and insignificant periosteum. Second trimester: The changes showed longitudinal growth of periosteal bone towards the proximal and distal ends of the growing bone. Growth plate with distinguished zones and gradual fusion of epiphysis with growth plate were observed. Third trimester: Trabeculation number and thickness increase with calcification. Towards the third trimester, the marrow cavity with increased and prominent trabeculations is consistent. Conclusion: Understanding normal microstructural and cellular events chronologically is an ideal platform for future studies to develop cell-based or cell-targeted therapies for adult bone disorders, traumatic bone injuries, or bone engineering. KEYWORDS: Histology, Developing Bone, Humerus, Fetuses, Embryology.

Comprehensive pan‑cancer analysis of MTDH for human tumor prognosis and as an immunological biomarker including breast and kidney cancer.

Metadherin (MTDH), initially discovered in primary astrocytes of the human fetus through rapid subtraction hybridization and labeled as astrocyte elevated gene-1, represents a widely recognized oncogene present in multiple types of cancers. However, the role of MTDH in different types of cancer remains unclear. To address this, a comprehensive analysis of MTDH across various types of cancers was conducted by utilizing multiple databases such as The Cancer Genome Atlas. The present analysis discovered that MTDH exhibits differential expression in different types of cancer and is associated with important factors including tumor mutational burden and microsatellite instability. These findings highlighted the significance of MTDH in the tumor microenvironment and its involvement in the development of immune cells in specific cancers. Furthermore, the results of the present study indicated that the expression of MTDH is strongly correlated with clinical prognosis, mutations and immune cell infiltration. MTDH could serve as a potential indicator of patient prognosis and potentially play a role in modulating the immune system. Given its potential as a novel immunological checkpoint, MTDH may be a viable target for tumor immunotherapy.

Transient contribution of the sphenoid ala major to the socket of the temporomandibular joint in near-term fetuses.

The temporomandibular joint (TMJ) is a complex structure that plays a vital role in the movement of the jaw. Some anatomy and dental textbooks show that, at the medial margin, the TMJ capsule attaches to a suture between the sphenoid ala major and the temporal bone squamosa. In near-term fetuses, the ala major extends posterolaterally to approach the TMJ. In this study, we aimed to investigate the contribution of the sphenoid ala major to the socket of the TMJ in near-term fetuses. We examined histological sections from 22 human fetuses (approximately 15-40 weeks). At midterm, the lateral and superior walls of the TMJ cavity were formed by the temporal bone squamosa, whereas the ala major was distant from the joint. However, at near-term, the ala major formed the medial wall of almost the entire part of the joint cavity. The top of the TMJ was attached to both the squamosa and ala major, with the condylar head consistently separated from the sphenoid by the joint disk. We observed a significant descent of the middle cranial fossa in near-term fetuses, which brought the ala major close to the TMJ. This transient position of the TMJ near the sphenoid is likely due to brain enlargement and posterolateral growth of the ala major. After birth, occlusion causes the anterior growth of the mandibular fossa of the squamosa, which moves the ala major away from the TMJ. Similarly, the lateral growth of the sphenoid toward the squamosa suture may also stop in children.

#2767 Micro(nano)plastics are exposed and bioaccumulated in human fetus—the first evidence from neonatal umbilical cord blood and urine

Abstract Background and Aims At present, the world population problem is increasingly serious, and the impact of environmental pollution on the health of pregnant women and fetuses is a global research focus. Among them, micro(nano)plastics (MNPs), as an emerging pollutant, has been confirmed by several animal experiments and in vitro human cell experiments to have biotoxic effects. Recent studies have shown that MNPs are found in human placenta, amniotic fluid, meconium, and other samples, but there is still a lack of direct evidence that MNPs can enter and bioaccumulate in the fetus. Method To initially explore the actual situation of neonatal exposure to MNPs, this study collected umbilical cord blood samples and postnatal urine samples from 6 healthy fetuses in Chengdu, Sichuan, China, and used pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and laser direct infrared spectroscopy (LDIR) to detect and analyze MNPs in samples. Results With an average abundance of 81.15 (40.71) μg/g, MNPs were found in 6 umbilical cord blood samples by Py-GC/MS. Polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS) and polyamide 66 (PA66), 4 different types of MNPs were found, with PE content being the highest among them. By using LDIR, MNPs were found in 5 umbilical cord blood samples, with an average abundance of 17.39 (18.91) particles/g. Three different types of MNPs were found, they are acrylates (ACR), polyethylene terephthalate (PET) and polypropylene (PP). MNPs particles were detected in 6 urine samples by PY-GC/MS, and the average abundance was 8.42 (4.70) μg/g. Two kinds of MNPs, PE and PVC, were detected, and the content of PE was higher. Conclusion The findings demonstrated that the contents and types of MNPs in umbilical cord blood samples were higher than those in urine samples. The levels of MNPs were correlated with the living habits of pregnant mothers, such as the frequency of ordering take-out food. In this study, through the detection of MNPs in umbilical cord blood and neonatal urine samples, we found the direct evidence of MNPs in the fetus for the first time, further confirmed that MNPs can enter the urine through renal metabolism, preliminarily explored the exposure and bioaccumulation effect of MNPs in the fetus, and analyzed the possible risks and related factors of exposure of MNPs during pregnancy, which provided a theoretical basis for in-depth study of the health impact of MNPs on pregnant women and fetuses.

Insertions of the striated muscles in the skin and mucosa: a histological study of fetuses and cadavers.

Striated muscle insertions into the skin and mucosa are present in the head, neck, and pelvic floor. We reexamined the histology of these tissues to elucidate their role in transmission of the force. We examined histological sections of 25 human fetuses (gestational ages of ~11-19 weeks and ~26-40 weeks) and 6 cadavers of elderly individuals. Facial muscle insertion or terminal almost always formed as an interdigitation with another muscle or as a circular arrangement in which muscle fiber insertions were sandwiched and mechanically supported by other muscle fibers (like an in-series muscle). Our examination of the face revealed some limited exceptions in which muscle fibers that approached the dermis were always in the nasalis and mentalis muscles, and often in the levator labii superioris alaeque nasi muscle. The buccinator muscle was consistently inserted into the basement membrane of the oral mucosa. Parts of the uvulae muscle in the soft palate and of the intrinsic vertical muscle of the tongue were likely to direct toward the mucosa. In contrast, the pelvic floor did not contain striated muscle fibers that were directed toward the skin or mucosa. Although 'cutaneous muscle' is a common term, the actual insertion of a muscle into the skin or mucosa seemed to be very rare. Instead, superficial muscle insertion often consisted of interdigitated muscle bundles that had different functional vectors. In this case, the terminal of one muscle bundle was sandwiched and fixed mechanically by other bundles.

CRANIOMETRICAL CHARACTERISTICS OF THE HUMAN FETAL SKULL

The purpose of the study – to ascertain the regularities of the age-related dynamics ofmorphometric changes of the skull in the fetal period of human ontogenesis.Material and methods. 59 specimens and 12 computed tomography (CT) scans of theskulls of human fetuses aged from 4 to 10 months of intrauterine development (IUD)were studied. A complex of morphological research methods was applied, which includedanthropometry, morphometry, three- dimensional reconstruction and statistical analysis.The results. It has been established that the longitudinal and transverse dimensions, thecircumference of the cerebral part of the skull grow almost uniformly before birth, but bythe 5th month of the IUD, a more accelerated growth is observed, due to which the scatterdiagram has the appearance of a logarithmic dependence. A somewhat uneven growth ofthese morphometric indicators is also observed in the age-related changes in the width andupper height of the face. The growth of the facial angle during the fetal period was revealed,which can be explained by the development of the mandible («pushing» it forward). At the same time, the basilar angle slightly decreases during the fetal period of development,which can be explained by the increase in the brain volume. The basilar angle increaseswith the age of the fetus, but somewhat unevenly in leptins, i. e., until the beginning of the6th month, it almost does not change, during the 6th-7th months it increases intensively,and then slows down again until the end of the fetal period of IUD. In euryons, there isa uniform growth of the basilar angle throughout the fruiting period of development, andmore intensively than in the average morphotype – mesens. Analysis of the correlation offetal age, cranial index, and basilar angle size showed even more significant anatomicalvariability. Thus, if in dolicho- and mesomorphs the basilar angle grows almost uniformlyduring the fetal period, then in brachymorphs it first intensively decreases until the 6thmonth of development, and then begins to grow until the newborn period. It should be notedthat a similar feature is observed in the dynamics of age-related changes in the facial angle,in addition to slowing down its growth from the 8th month in dolichomorphs.Conclusions. 1. Regression analysis of the correlation of age, morphotype indicators, andbasilar and facial angles made it possible to establish patterns of individual morphometricvariability of the skull in the dynamics of the fetal period of prenatal human development,as well as to identify critical periods of morphogenesis of the brain and facial parts ofthe skull, which are 6-7 months in leptins, the 6th month – for brachymorphs and the 8thmonth – for dolichomorphs. 2. The size of the basilar angle of the skull is an importantdiagnostic and prognostic indicator in combination with indices that characterize themorphotype of the individual, for monitoring the normal development of the skull andbrain of the fetus.

Pomoc w przerywaniu ciąży – art. 152 § 2 Kodeksu karnego na kanwie sprawy Justyny Wydrzyńskiej

This text is devoted to the examination of Article 152 § 2 of the Penal Code. It criminalizes aiding or abetting an abortion, as referred to in Article 152 § 1 of the Penal Code. The consideration here is limited to the issue of aiding and abetting. The case of Justyna Wydrzyńska, convicted (inconclusively, at the time of this writing) in the first instance by the Warsaw-Praga District Court in Warsaw, (ref. no. V K 18/22) under Article 152 § 2 of the Criminal Code at an in camera hearing, is the basis for the reflections. The matter is noteworthy because of the existence of this provision in a legal reality in which there is a systemic violation of the authorities' obligations to respect reproductive rights. These arise from the 1993 law, on family planning, protection of the human fetus and the conditions for permissible termination of pregnancy. Hence, it is legitimate to analyze Article 152 § 2 of the Penal Code in the context of the provisions of that law and considering the evolving relationship between "aiding and abetting" as included in Article 152 § 2 of the Penal Code and the statutory definition of aiding and abetting contained in Article 18 § 3 of the Penal Code. For the question arises, if Article 152 § 2 of the Penal Code refers to the Family Planning Act, does this refer only to the grounds for abortion included therein, or does it also require, as we contend, consideration of the statutory conditions on reproductive rights that the Act sets? We base our view on respect for the purpose-driven legal interpretation and on preamble to the Planning Law. Preamble is not merely a solemn introduction. It's binding the authorities to act in way that secure reproductive rights provided in the 1993 Law. We claim that in the case cited, the Warsaw-Praga Regional Court, in finding that the elements of Article 152 § 2 of the Criminal Code were fulfilled, did not consider the totality of the circumstances allowing for a different assessment. We point out the facts and cite arguments in favor of concluding that in the established state of facts no crime was committed. That it is reasonable in this case to assume a state of superior necessity or to consider that the circumstances included in Article 1 § 2 and § 3 of the Criminal Code are present. We rely on the case of Justyna Wydrzynska, but our reasoning goes further. Indeed, the case of the prosecution of Justyna Wydrzynska illustrates a situation in which a pattern of law applied in disregard of the conditions under which it operates leads to a flawed interpretation that expands criminalization. This is contrary to the principles of criminal law. The objection expressed in this text to the use of an extensive legal interpretation. It is in line with the current interpretation that eliminates from the Article 152 § 2 of the Criminal Code the aiding and abetting in the form of "transferring information. It is " even though this is one of the prerequisites for recognizing in Article 18 § 3 of the Criminal Code that aiding and abetting has occurred. "Transmission of information" thus falls within the statutory concept of aiding and abetting but does not apply to the elements of Article 152 § 2 of the Criminal Code. We prove that, similarly, despite the exhaustion of the statutory elements of the crime of Article 152 § 2 of the Penal Code, when the thing concerns an action aimed at protecting the endangered good, which is the health and life of a woman, despite the exhaustion of the statutory elements of Article 152 § 2 of the Penal Code, the circumstances included in Article 26 § 1 and § 2 of the Penal Code are present and the circumstances referred to in Article 1 § 2 and § 3 for stating absence of crime of the Penal Code are present.

Sexual dimorphism of the human fetal pelvis exists at the onset of primary ossification

Human adolescent and adult skeletons exhibit sexual dimorphism in the pelvis. However, the degree of sexual dimorphism of the human pelvis during prenatal development remains unclear. Here, we performed high-resolution magnetic resonance imaging-assisted pelvimetry on 72 human fetuses (males [M]: females [F], 34:38; 21 sites) with crown-rump lengths (CRL) of 50–225 mm (the onset of primary ossification). We used multiple regression analysis to examine sexual dimorphism with CRL as a covariate. Females exhibit significantly smaller pelvic inlet anteroposterior diameters (least squares mean, [F] 8.4 mm vs. [M] 8.8 mm, P = 0.036), larger subpubic angle ([F] 68.1° vs. [M] 64.0°, P = 0.034), and larger distance between the ischial spines relative to the transverse diameters of the greater pelvis than males. Furthermore, the sacral measurements indicate significant sex-CRL interactions. Our study suggests that sexual dimorphism of the human fetal pelvis is already apparent at the onset of primary ossification.

Unveiling the vulnerability of the human abducens nerve: insights from comparative cranial base anatomy in mammals and primates.

The topographic anatomy of the abducens nerve has been the subject of research for more than 150 years. Although its vulnerability was initially attributed to its length, this hypothesis has largely lost prominence. Instead, attention has shifted toward its intricate anatomical relations along the cranial base. Contrary to the extensive anatomical and neurosurgical literature on abducens nerve anatomy in humans, its complex anatomy in other species has received less emphasis. The main question addressed here is why the human abducens nerve is predisposed to injury. Specifically, we aim to perform a comparative analysis of the basicranial pathway of the abducens nerve in mammals and primates. Our hypothesis links its vulnerability to cranial base flexion, particularly around the sphenooccipital synchondrosis. We examined the abducens nerve pathway in various mammals, including primates, humans (N = 40; 60% males; 40% females), and human fetuses (N = 5; 60% males; 40% females). The findings are presented at both the macroscopic and histological levels. To associate our findings with basicranial flexion, we measured the cranial base angles in the species included in this study and compared them to data in the available literature. Our findings show that the primitive state of the abducens nerve pathway follows a nearly flat (unflexed) cranial base from the pontomedullary sulcus to the superior orbital fissure. Only the gulfar segment, where the nerve passes through Dorello's canal, demonstrates some degree of variation. We present evidence indicating that the derived state of the abducens pathway, which is most pronounced in humans from an early stage of development, is characterized by following the significantly more flexed basicranium. Overall, the present study elucidates the evolutionary basis for the vulnerability of the abducens nerve, especially within its gulfar and cavernous segments, which are situated at the main synchondroses between the anterior, middle, and posterior cranial fossae-a unique anatomical relation exclusive to the abducens nerve. The principal differences between the pathways of this nerve and those of other cranial nerves are discussed. The findings suggest that the highly flexed human cranial base plays a pivotal role in the intricate anatomical relations and resulting vulnerability of the abducens nerve.

Mentalis nerve branches supplying the lower lip revisited: a study of human fetuses and donated elderly cadavers.

Little information is known about the mentalis nerve course from the lower lip approximation margin (free margin) to the upper lip. Likewise, no difference in nerve distribution has been observed between the cutaneous and mucosal parts of the lip. Therefore, this study reexamined mentalis nerve morphology. For macroscopic observations, three fresh cadavers were dissected (one male and two females; aged 78-93). We also evaluated histological sections obtained from five donated elderly cadavers (two males and three females, aged 82-96 years) and 15 human fetuses (11-40 weeks or crown-rump length 80-372mm). Immunohistochemical analysis for S100 protein and tyrosine hydroxylase was performed. In both fetuses and adult cadavers, one to three nerve branches ran upward in the submucosal tissue from the mental foramen. Near the free margin of the lip, some branches passed through the orbicularis oris muscle layer toward the lip skin, whereas others followed a reversed J-shaped course along the free margin. Nerve twigs ran in parallel beneath the mucosa, whereas wavy nerve twigs attached to the basal lamina of the lip epidermis. The difference in nerve endings abruptly occurred at the skin-mucosal junction. Tyrosine hydroxylase-positive sympathetic nerve twigs surrounded arteries and formed a branch composed of S100-negative unmyelinated fibers. The lower lip skin was innervated by a perforating branch passing through the orbicularis oris muscle, that was different from the lip mucosa. A sudden change in the nerve ending configuration at the mucocutaneous junction seemed to develop postnatally.

Molecular stratification of the human fetal vaginal epithelium by spatial transcriptome analysis.

The human vaginal epithelium is a crucial component of numerous reproductive processes and serves as a vital protective barrier against pathogenic invasion. Despite its significance, a comprehensive exploration of its molecular profiles, including molecular expression and distribution across its multiple layers, has not been performed. In this study, we perform a spatial transcriptomic analysis within the vaginal wall of human fetuses to fill this knowledge gap. We successfully categorize the vaginal epithelium into four distinct zones based on transcriptomic profiles and anatomical features. This approach reveals unique transcriptomic signatures within these regions, allowing us to identify differentially expressed genes and uncover novel markers for distinct regions of the vaginal epithelium. Additionally, our findings highlight the varied expressions of keratin ( KRT) genes across different zones of the vaginal epithelium, with a gradual shift in expression patterns observed from the basal layer to the surface/superficial layer. This suggests a potential differentiation trajectory of the human vaginal epithelium, shedding light on the dynamic nature of this tissue. Furthermore, abundant biological processes are found to be enriched in the basal zone by KEGG pathway analysis, indicating an active state of the basal zone cells. Subsequently, the expressions of latent stem cell markers in the basal zone are identified. In summary, our research provides a crucial understanding of human vaginal epithelial cells and the complex mechanisms of the vaginal mucosa, with potential applications in vaginal reconstruction and drug delivery, making this atlas a valuable tool for future research in women's health and reproductive medicine.