Fetal Research Articles

Verniks Kazeoza Maddesinde Bulunan Bazı Element (Na+, Cl-, K+, Fe+2, Mg+2, Ca+2, Cu+2, Zn+2) Düzeylerinin Değerlendirilmesi

The substance "Vernix Caseosa" (VC), which begins to be secreted in the third trimester of the human fetus, is a natural product that occurs spontaneously. This substance, which protects the baby against external factors, has a feature that facilitates birth by providing lubrication during normal birth. 52 infants were included in the study. A sterile soft-tipped device was used to collect the VC, and a swab was taken from the baby's skin immediately after birth. In addition, mothers under the age of 35 and over the age of 35 were grouped as multiparous and nulliparous and their VC was examined separately. In VC, the levels of the elements responsible for production and repair in the human body were investigated. Homogenized samples were measured by Atomic Absorption Spectrophotometer. Element results were given as mean and standard deviation; *Na+: 12.09 ± 0.58, *Cl-: 10.27 ± 1.08, *K+:1.84 ± 0.54, **Fe+2: 72.39 ± 4.84, **Mg+2: 67.07 ± 3.31, **Ca+2:864.51 ± 32.61, **Cu+2:12.98 ± 2.01, **Zn+2: 11.00 ± 1.55 (*:mg/g tissue, **:ug/g tissue). According to the results of literature review and to the best of knowledge, limited information on element levels of VC has been reported. The studied elements are found as cofactors in growth and development and in many biochemical mechanisms. Protein and lipid contents have been investigated in previous studies and it has been reported that VC has an important role in protecting the fetus from external factors and infections. In addition, the protection of amniotic fluid from maceration and the prevention of fluid and electrolyte losses of the skin are also mentioned. It is thought that this research will make an important contribution to the determination of the biochemical structure of VC, which is a natural and protective substance.

An Immunohistochemical Study of Proliferation of Human Fetal Heart Cardiomyocyte With Phospho-Histone H3 Antibody.

The rapid proliferation of cardiomyocytes in mammals occurs during fetal life. But in postnatal life, this capacity of proliferation is reduced or lost as they exit the cell cycle. However, the cardiomyocytes don't show the same activity for different species. In human fetuses orin adult life, the capacity of the proliferation of cardiomyocytes and their response to an injury arenot understood yet.In this study, we have done an immunohistochemical study using phospho-histone H3 (PHH3) to observe human fetal cardiomyocytes' proliferative activity. The heart specimens from the fetal autopsy of spontaneously aborted and stillborn human fetuses were subjected to immunohistochemical study using PHH3 antibody, and comparison between the PHH3 index (number of PHH3 positive cells per 1000 number of cardiomyocytes/high power field [HPF]) of myocardial regions was done using appropriate statistical tests. A total of 17 fetal hearts were included in our study. In the left ventricle, right ventricle, right atrium, and interventricular septum, the PHH3 index of myocardium was significantly higher over the pericardial region (p-value 0.002, p-value <0.001, <0.001, and 0.009 respectively) as compared to the region of over the endocardium and the middle part of the myocardium.The PHH3 index of the pericardial region of the left ventricle was significantly correlated with the maximum thickness of the left ventricle.

Immunohistochemical characteristics of the gray matter of the human spinal cord in the late prenatal period

The study is dedicated to the relevant problem of studying the patterns of age-related (prenatal) restructuring in the brain and spinal cord and provides opportunities for predicting and correcting the occurrence of congenital defects. The aim of the research was to establish the nature of immunohistochemical marker expression in the gray matter structures of the human spinal cord during the late prenatal period. The material for the study consisted of spinal cord preparations from 27 human fetuses at gestational age 35-40 weeks. The following methods were used during the research: anatomical, general histological, special histological, immunohistochemical, morphometric, and statistical analysis of the obtained data. It was found that at 35-36 weeks of the gestational period, the proliferation of neural stem cells (NSCs) occurs more intensively in the ventral neuroepithelium of spinal cord segments compared to the dorsal neuroepithelium. In the ventral neuroepithelium, there are 5-6 mitotic or post-mitotic NSCs, while in the dorsal part, there are only 2-3 cells. In fetuses at 39-40 weeks, the proliferative activity of neural stem cells in the dorsal neuroepithelium is higher in cervical and lumbar segments, where Ki-67 expression is detected in 6 % of cells (reactive in 7-8 cells), and in thoracic and sacral segments, it is 4 % (reactive in 3-4 cells). In contrast to the dorsal neuroepithelium, in the ventral part of the neuroepithelium of the segments, the proliferative activity of neural stem cells is slightly less intense. In cervical and lumbar segments, Ki-67 expression occurred in 4 % of cells (reactive in 3-4 cells), and in thoracic and sacral segments, it was 2 % (reactive in 1-2 cells). At 35-36 weeks of gestation, high vimentin expression was observed around the neuroepithelium, at the base of the posterior horns, and along the posterior median septum. Vimentin expression in the mantle layer was relatively weak and persisted along blood vessels and in the area of spinal cord root formation. Before birth, relatively weak vimentin expression was detected in the remnants of radial glia surrounding the neuroepithelial layer. Vimentin expression was absent in the neuroepithelium proper, but focal vimentin expression was observed around blood vessels. The absence of vimentin expression in the neuroepithelium indicates the disappearance of radial cells. At 35-40 weeks of the gestational period, relatively strong synaptophysin expression was observed in the mantle layer of spinal cord segments, indicating the intensity of neuronal connectivity establishment and myelination of nerve fibers. These processes continue after birth. Synaptophysin expression was absent in the neuroepithelium proper.

P-758 Impact of serum estradiol levels prior to progesterone administration in artificial frozen embryo transfer cycles:a retrospective study over 26,000 cycles

Abstract Study question To investigate whether serum estradiol (E2) levels prior to progesterone administration in the FET-cycle affect the Clinical pregnancy rate (CPR) and live birth rate (LBR). Summary answer High serum E2 levels prior to progesterone administration in Artificial endometrial preparation are associated with a decreased live birth rate and clinical pregnancy rate . What is known already Although the use of FET has progressively increased, it is still unknown whether a specific endometrial preparation protocol should be favored over another. Owing to their minimal need for clinic visits and a larger scheduling flexibility, artificial cycles for FET are widely used. Additional to the ultrasonographic endometrial thickness check prior to FET, the need for endocrine monitoring in artificial cycles remains unclear. Specifically, the value of proliferative phase serum hormone measurements remains a point of discussion. Study design, size, duration A total of 26,194 artificial FETs performed in a Tertiary-care academic medical centre between 2016 and 2021 were subdivided into 3 groups according to the following late-proliferative serum E2 level percentiles: ≤p33.3 (E2 ≤118 pg/ml; n = 8784), p33.4–p66.6 (E2 from 118.1 to 231.9 pg/ml; n = 8662) and ≥p66.7 (E2 ≥232 pg/ml; n = 8748). Participants/materials, setting, methods A retrospective study over 26,194 cycles,from 2016 to 2021 were included.Univariable and multivariable logistic regression analysis was performed. Main results and the role of chance In 26,194 cycles, there were significant differences in CPR and LBR among the tri-sectional quantiles groups with E2 levels. After stratifying the analysis by age, BMI, infertility diagnosis, type of embryo transferred, number of transferred embryos, infertility factors, method of fertilization, and endometrial thickness on transfer day, there were still significant differences in CPR and LBR among the tri-sectional quantiles group with E2 levels. Multivariate regression analysis showed that female age, thin endometrium, high serum E2 level, tubal factor infertility were risk factors for CPR and LBR, ICSI fertilization, blastocyst transfer, the number of transferred embryos, ovulation disorder infertility and male factor infertility were protective factors for CPR and LBR, BMI was only a risk factor for LBR. Limitations, reasons for caution •Different routes of administration affect serum estrogen levels,and the relationship of serum estrogen levels and endometrial estrogen concentrations is unclear Wider implications of the findings High miscarriage rate following FET has been a point of debate in literature.Future research should definitely focus on the the usefulness of serum E2 evaluation to optimize the success rate. Trial registration number Not applicable

Morphology of the bifid xiphoid process or foramen: is there a difference in cadaver or imaging?

Context: Anatomical variations of the sternum are frequent, in particular, the occurrence of foramina and divisions of the xiphoid process. The authors have used means of investigation ranging from dissection to imaging tests to detect these variations. Objective: To report a case of bifid xiphoid process in a male human fetus and/or xiphoid foramen through macroscopic analysis, complemented by the use of X-ray image. Case report: Anatomical variations were found at the level of the xiphoid appendix of the sternum such as a bifid formation of the appendix and a foramen found on X-ray imaging, located in the middle of a fibrous tissue that separated the two divisions of the xiphoid process. Conclusion: The present findings point to the need for greater collaboration in the use of other methods for studying the anatomical variations of the sternum. For example, Multidetector Computed Tomography (MDCT). This will be of great value to anatomists and specialists in imaging diagnostics.

ATRT-10. SINGLE-CELL TRANSCRIPTOME ANALYSIS REVEALS CELLULAR HIERARCHIES AND THERAPEUTIC VULNERABILITIES OF ETMR

Abstract Embryonal tumors with multilayered rosettes (ETMR) are malignant brain tumors that occur predominantly in infants and young children. Most patients die within two years of diagnosis, and more effective, targeted therapies are urgently needed. To better characterize the oncogenic mechanisms of key driver alterations and to identify novel therapeutic targets, we set out to study the cellular heterogeneity of ETMR using single-cell RNA sequencing. Analyses conducted on &amp;gt;4,000 high-quality cells collected from eleven primary and relapse specimens revealed a common cellular hierarchy across all tumors: A highly proliferative neural stem cell-like population (SOX2+) that gives rise to intermediate progenitors (NEUROD1/NEUROG1+) and more differentiated neuron-like cells (STMN2/4+). These malignant cell populations closely overlap with histological patterns of ETMRs, as confirmed by multiplexed immunofluorescence microscopy on patients’ tumors. Comparison to single-cell datasets from human fetuses indicated high resemblance to normal cortical neurogenesis but also revealed key tumor-specific differences. These include expression of the chromosome 19 miRNA cluster (C19MC, the presumed driver in ~90% of ETMRs), which was restricted to the malignant stem cell-like population. Investigating oncogenic mechanisms of C19MC (comprising 46 miRNA genes) through transcriptome-wide RNA immunoprecipitation analysis, we identified extensive target gene regulation for most C19MC members, including distinct regulators of cell cycle, pluripotency, and neuronal differentiation. Silencing of C19MC families with antisense oligonucleotides resulted in pronounced reduction of ETMR cell line growth, indicating potential avenues for therapeutic targeting in the future. To identify more immediately actionable targets, we investigated inter-cellular signaling between malignant cell populations of ETMRs. Interestingly, we identified marked FGFR and NOTCH receptor-ligand interactions common to all tumors. An in vitro screen of experimental and approved small molecule inhibitors designed to target these interactions nominated several promising candidates for clinical evaluation. Our unpublished results provide much needed insight into targeting ETMR cellular states using multiple modes of action.

Characteristic findings in the human fetus vestibule: A human temporal bone study

ObjectiveThe “collapse,” a highly flexed, dented, or caved membrane between the endo- and peri-lymph of the saccule and utricle in adults, is considered as a morphological aspect of Ménière's syndrome. Likewise, when mesh-like tissues in the perilymphatic space are damaged or lost, the endothelium loses mechanical support and causes nerve irritation. However, these morphologies were not examined in fetuses. MethodsBy using histological sections from 25 human fetuses (crown-rump length[CRL] 82–372 mm; approximately 12–40 weeks), morphologies of the perilymphatic-endolymphatic border membrane and the mesh-like tissue around the endothelium were examined. ResultsThe highly flexed or caved membrane between the endo- and peri-lymphatic spaces was usually seen in the growing saccule and utricle of fetuses, especially at junctions between the utricle and ampulla at midterm. Likewise, the perilymphatic space around the saccule, utricle and semicircular ducts often lost the mesh-like tissues. The residual mesh-like tissue supported the veins, especially in the semicircular canal. ConclusionWithin a cartilaginous or bony room showing a limited growth in size but containing increased perilymph, the growing endothelium appeared to become wavy. Owing to a difference in growth rates between the utricle and semicircular duct, the dentation tended to be more frequently seen at junctions than at free margins of the utricle. The difference in site and gestational age suggested that the deformity was not “pathological” but occurred due to unbalanced growth of the border membrane. Nevertheless, the possibility that the deformed membrane in fetuses was an artifact caused by delayed fixation is not deniable.

Prostate Gland in Human Foetuses: A Study of its Histogenesis

Background: To study the histogenesis of the prostate gland in human foetuses. ‘Prostates’ is a Greek word which literally means “one who stands before”, protector, guardian. It is important from a clinical point of view as it undergoes benign enlargement from the fifth decade, hence attracting the attention of males around this age and simultaneously the clinicians. Materials and Methods: 100 foetuses of different gestational ages ranging from 14 weeks (85 mm) to 40 weeks (440 mm), products of terminated pregnancies under Medical Termination of Pregnancy, MTP Act of India, 1971 and stillbirths were collected from the Department of Obstetrics and Gynaecology, RIMS, (Regional Institute of Medical Sciences), Imphal, Manipur and utilised for the present study with permission from the Institutional Ethical Committee. Results and Discussion: The first sign of differentiation is recognised as increased cellularity and denser mesenchymal cells. Cytoarchitecture at specific age period at different age groups are described. Conclusion: Cytoarchitecturally, differentiation of all the three components of the prostate gland was noted as the age changes. It is inferred that of the three components of the adult tissues, the glandular component is differentiated from the epithelial lining of the urethra. This further induces the early mesenchymal tissues to differentiate into muscles and fibrous components. And at term, it has all the three components of the adult tissues although it is not as mature as in adult. KEY WORDS: Prostate gland, human foetuses, histogenesis and cytoarchitecture.

Ultra-high-field MRI of postmortem human fetal wrist joints: initial experience

BackgroundThis study aimed to assess the feasibility of postmortem ultra-high-field magnetic resonance imaging (UHF-MRI) to study fetal musculoskeletal anatomy and explore the contribution of variation in iodine and formaldehyde (paraformaldehyde, PFA) treatment of tissue.MethodsSeven upper extremities from human fetuses with gestational ages of 19 to 24 weeks were included in this experimental study, approved by the Medical Research Ethics Committee. The specimens were treated with various storage (0.2–4% PFA) and staining (Lugol’s solution) protocols and the wrist joint was subsequently imaged with 7.0 T UHF-MRI. Soft-tissue contrast was quantified by determining regions of interest within a chondrified carpal bone (CCB) from the proximal row, the triangular fibrocartilage (TFC), and the pronator quadratus muscle (PQM) and calculating the contrast ratios (CRs) between mean signal intensities of CCB to TFC and CCB to PQM.ResultsUHF-MRI showed excellent soft-tissue contrast in different musculoskeletal tissues. Increasing storage time in 4% PFA, CRs decreased, resulting in a shift from relatively hyperintense to hypointense identification of the CCB. Storage in 0.2% PFA barely influenced the CRs over time. Lugol’s solution caused an increase in CRs and might have even contributed to the inversion of the CRs.ConclusionsUHF-MRI is a feasible technique to image musculoskeletal structures in fetal upper extremities and most successful after short storage in 4% PFA or prolonged storage in 0.2% PFA. The use of Lugol’s solution is not detrimental on soft-tissue MRI contrast and therefore enables effectively combining UHF-MRI with contrast-enhanced micro-computed tomography using a single preparation of the specimen.Relevance statementUHF-MRI can be performed after CE-micro-CT to take advantage of both techniques.Key points• UHF-MRI is feasible to study human fetal cartilaginous and ligamentous anatomy.• Storage in low PFA concentrations (i.e., 0.2%) improves soft-tissue contrast in UHF-MRI.• Limited preservation time in high concentrations of PFA improves soft-tissue contrast in UHF-MRI.• Prior staining with Lugol’s solution does not reduce soft-tissue contrast in UHF-MRI.Graphical

Morphogenesis of the human brain and cerebellum in the early prenatal period

Annotation. Neurogenesis is a complex process of neuron formation that is central to the formation of most neurons in the human brain during vertebrate development. The purpose of this study was to establish and compare the parameters of the cerebellum and the endbrain of humans at 8-9 weeks of intrauterine development, as well as the features of cytoarchitectonics, which is inherent in the studied period of gestation. In the process of scientific research, 10 fetuses of 8-9 weeks were examined and research methods were applied, such as: immunohistochemical, anatomical-histological and morphometric. The morphometric study was carried out using a light microscope MBS-10 and SIGETA. Studies were performed at magnifications of ×4, ×10, ×20, ×40, and ×100. From the obtained histological sections, photofixation and morphometry were performed using the ETREK Ucmos camera and the ToupViem computer program (computer histometry). Statistical processing of digital data was applied using the software package “Statistica 6.0” from Statsoft (license number BXXR901E246122FA). During the study, we observed that the total thickness of the studied area varied depending on the part of the endbrain. In the hemispheres of the endbrain of 8-9 week fetuses, the presence of such layers as ventricular, subventricular, intermediate and cortical was noted, whereas examining the cerebellum, we witnessed the presence of the ventricular zone, intermediate, molecular and external granular zone. The expression of proliferated neural stem cells in the layers of the endbrain was the most active in the ventricular zone, compared to the others. Migration of neural stem cells in the cerebellum, in the ventricular and external granular zones occurs in two directions: tangential and radial. Weak expression of synaptophysin is observed in the cerebellum. In the endbrain, synaptophysin expression was strong in the intermediate and cortical zones. Fibers of radial glia of an 8-9 week fetus penetrate all zones of the endbrain and cerebellum. On a horizontal histological section of the terminal brain of human fetuses, the cavities of the ventricles were visualized and the development of vascular plexuses in the lateral ventricles of the brain was noted. Thus, in the course of the research, we compared the features of cytoarchitectonics, morphometric parameters of the structures of the endbrain and cerebellum of human fetuses of 8-9 weeks of intrauterine development.

PROJECTION FETAL ANATOMY VASCULAR AND NERVOUS FORMATIONS OF THE ANTERIOR REGION OF THE ARM

Abstract. In the case of gunshot wounds, the upper extremities prevail poly-structural injuries, primarily characterized by damage to nerve trunks, vessels, soft tissues, and bones. Compartment syndrome is one of the most di ffi cult pathological conditions underlying the majority of fi rearm complications is injuries of the limbs and, above all, those accompanied by bone fractures and limbs, and can lead to permanent disability.Until now, fetal patterns have not been defi nitively clarifi ed in the topography of fascial- muscular formations, fi ber spaces, and projection anatomy of the vascular and nervous structures of the anterior region of the arm at diff erent stages of human ontogenesis.The study aimed to establish the vascular- nervous projection structures of the anterior arm region in human fetuses.The study was conducted on preparations of the upper limbs of 48 human fetuses aged from 4 to 10 months using macromicroscopic dissection, injection of vessels, and morphometry.It was established that in human fetuses the projection of the main vascular of the nerve bundle of the shoulder on the skin corresponds to the line that connects the point between the middle and front thirds of the width of the axillary fossa to the middle ulnar fossa. The median nerve in the upper third of the shoulder is determined near the medial edge of the biceps muscle of the shoulder, as a rule, laterally of the brachial artery, within the middle of the anterior region of the arm, median the nerve crosses the brachial artery in front and goes straight in the lower third of the shoulder approximately from the brachial artery. Projection of the ulnar nerve within the upper third of the anterior region of the arm corresponds to the projection of the main vascular- nerve bundle, within the middle and lower thirds – the line that connects the middle of the medial bicipital groove of the shoulder with the medial epicondyle of the humerus. An anatomical landmark for the determination of topography of the main vein, the median cutaneous nerve of the forearm and of the median nerve is the medial edge of the biceps muscle of the shoulder, and the lateral edge of this muscle is a landmark for identifying the main vein.Obtained data on fetal and projection anatomy of structures of the anterior region of the arm in human fetuses of diff erent ages have an important role and applied value and will reduce the risk of iatrogenic injuries and exclude the possibility of developing vascular and nervous complications in the postoperative period, choose the correct tactics of operative interventions in the anterior region of the arm.

TOPOGRAPHIC AND ANATOMICAL RELATIONSHIPS OF INTRAMUSCULAR ARTERIES AND NERVES IN THE SHOULDER REGION OF HUMAN FETUSES

In modern surgical practice, there is a growing need to improve techniques of operative interventions. Despite advancements in diagnosis and treatment, combined shoulder injuries remain a pressing problem. In the past, surgical intervention for combined trauma primarily focused on saving the patient's life. However, today it is essential not only to preserve life but also to restore the function of the injured structures. Humerus fractures are observed in 27.9% of polytrauma cases, significantly complicating urgent diagnostic and treatment procedures and worsening the patient's condition. A comprehensive study of the topographical and anatomical relationships of intramuscular arteries and nerves at the shoulder level can facilitate the selection of optimal surgical approaches, prevent iatrogenic damage, and contribute to the patient's rapid rehabilitation.&#x0D; The objective of this study was to identify the distribution patterns of arteries and nerves at different levels of the shoulder in human foetuses.&#x0D; Materials and Methods. The study involved the examination of upper limb preparations from 48 human foetuses, ranging from 81.0 to 370.0 mm in parietal-caudal length without external signs of anatomical deviations or anomalies in the development of the skeletal and muscular structures of the upper limbs. Macromicroscopic dissection, vessel injection, and morphometry techniques were employed.&#x0D; Results and Discussion. In human foetuses, the upper and middle thirds of the shoulder were found to have the highest concentration of intramuscular arteries and nerves. The entry points of arteries and nerves, their topography and branching patterns within the shoulder muscles did not always align. Arterial branches generally entered the muscles at slightly more distal locations than the nerve trunks, following the shortest path to reach the muscles.&#x0D; The levels at which arteries and nerves start branching to supply and innervate the muscles of the anterior and posterior shoulder groups, vary in human foetuses. This variation depends on the individual anatomical variability of the major vascular and nerve trunks.&#x0D; Conclusion: The levels of arterial and nerve abduction are related to the topographic and anatomical features of a particular shoulder muscle. Considering the topography of intramuscular arteries and nerves, it is advisable to perform incisions along the direction of muscle bundles, particularly near the lower border of the neurovascular unit of the brachial biceps. This approach can offer higher clinical and surgical effectiveness.

Quantitative study of the primary ossification centre of the parietal bone in the human fetus.

Detailed morphometric data concentrating on the development of primary ossification centres in human fetuses is critical for the early detection of developmental defects. Thus, an understanding of the growth and development of the parietal bone is crucial in assessing both the normal and pathological development of the calvaria. The size of the parietal primary ossification centre in 37 spontaneously aborted human fetuses of both sexes (16 males and 21 females) aged 18-30 weeks was studied by means of computed tomography, digital-image analysis and statistics. The numerical data of the parietal primary ossification centre in the human fetus displays neither sex nor laterality differences. With relation to fetal age in weeks, the parietal primary ossification centre grew in sagittal diameter according to the quadratic function: y = 16.322 + 0.0347 × (age)² ± 1.323 (R² = 0.96), in projection surface area according to the cubic function: y = 284.1895 + 0.051 × × (age)³ ± 0.490, while in both coronal diameter and volume according to the quartic functions: y = 21.746 + 0.000025 × (age)⁴ ± 1.256 and y = 296.984 + + 0.001 × (age)⁴, respectively. The obtained morphometric data of the parietal primary ossification centre may be considered age-specific references, and so may contribute to the estimation of gestational ages and be useful in the diagnostics of congenital cranial defects.

Cavitation processes in a space filled with loose mesenchymal tissues: a comparison between the retrosternal space and the middle ear tympanic cavity in human fetuses.

During the expansion of the pleural cavity in early fetuses, a thick sheet of loose mesenchymal tissue (SLMT) appears between the lung bud and body wall. Subsequently, the growing lung bud invades into the SLMT and the latter becomes fragmented to disappear. To compare this with the tympanic cavity filled with loose mesenchymal tissues, the present study aimed to demonstrate the development, establishment, and breaking of the SLMT in the retrosternal space. Although the retrosternal tissue was almost absent or very thin at 7 weeks, the SLMT appeared behind the manubrium sterni at 8 weeks. Accordingly, at 9-10 weeks, cavitation occurred in the SLMT to expand the pleural cavity. Therefore, the volume of SLMT was not determined by the adjacent structures such as the pericardium and sternum. Likewise, mesenchymal tissues filling the middle ear disappeared after 26 weeks. There were considerable individual variations in the timing of beginning and location of the tympanic cavitation. However, in contrast to the retrosternal SLMT, the volume of the future tympanic cavity is determined by the adjacent hard tissue and tympanic membrane much earlier than the cavitation. The mesenchymal tissue carried abundant vessels in the middle ear but none or few veins in the retrosternal SLMT. The concept that the lung bud invades into the splanchnic mesoderm to expand the pleural cavity seems oversimplified. Mechanical stresses from the pleural cavity might induce retrosternal cavitation, while a loss in blood supply might cause tympanic cavitation.

Morphological variability of the pectoralis major muscle in human fetuses

BackgroundThe pectoralis major muscle is located in the anterior chest wall. In most cases, it is divided into clavicular, sternal (sternocostal) and abdominal heads. The aim of this study is to demonstrate and classify the morphological variability of the pectoralis major muscles in human fetuses. Material and methodsClassical anatomical dissection was performed on 35 human fetuses aged 18–38 weeks of gestation at death were examined. (17 female, and 18 male, 70 sides; fixed in 10% formalin solution). The fetuses were obtained from spontaneous abortion after informed consent of both parents and through deliberate donation to the Medical University anatomy program. Upon dissection, the following morphological features were assessed: the morphology of the pectoralis major, the possible occurrence of accessory heads, the possible absence of some head, and morphometric measurements of each head of the pectoralis major muscle. ResultsFive types of morphology (based on number of bellies) were observed in the fetuses. Type I was characterized by a single claviculosternal belly (10% of all samples). Type II comprised the clavicular and sternal heads (37.1%). Type III comprised three clavicular, sternal and abdominal heads (31.4%). Type IV (17.2%) was characterized by four muscle bellies and was divided into four subtypes. Type V (4.3%), was represented by five parts, and was divided into two subtypes. ConclusionsDue to its embryological development, the PM demonstrates great variability in the numbers of its parts. The most common type was the PM with two bellies, in line with previous studies which also distinguished only clavicular and sternal heads.

Visualizing alpha-fetoprotein level in undiluted serum based on microfluidic particle accumulation

Alpha-fetoprotein (AFP) is an abundant plasma protein produced by the liver of the human fetus. When abnormally elevated in adult serum, its level can be an essential biomarker for various cancers. In addition, maternal AFP serum levels can be used to screen congenital disorders such as down syndrome and neural tube defects. Here, we report a portable method for visualizing AFP levels in serum. Magnetic microparticles (MMPs) and polystyrene microparticles (PMPs) are designed to bind with AFP simultaneously. By loading the particle solution into a microfluidic chip with a magnetic separator, unconnected PMPs can be separated and continue flowing forward until being trapped at a particle dam. Ultimately, the accumulation length of PMPs enables visualization of AFP levels. This device can be adapted to sensitive mode (70 min incubation) with a limit of detection (LOD) of 15.8 ng/ml and rapid mode (15 min incubation) with a LOD of 34.3 ng/ml in undiluted serum samples, providing a strategy for fast and visual quantitative detection of serum AFP.

Neuronal progenitors of the dentate gyrus express the SARS-CoV-2 cell receptor during migration in the developing human hippocampus

The COVID-19 pandemic spread around the world is due to the enormous capacity of the SARS-CoV-2 coronavirus to be transmitted between humans, causing a threat to global public health. It has been shown that the entry of this virus into cells is highly facilitated by the presence of angiotensin-converting enzyme 2 (ACE2) in the cell membrane. Currently, we have no precise knowledge of how this receptor expresses in the brain of human fetus and, as a consequence, we do not know how susceptible the neural cells in the developing brain are to being infected through the vertical transmission of this virus, from mother to fetus. In this work, we describe the expression of ACE2 in the human brain at 20 weeks of gestation. This stage corresponds to the period of neuronal generation, migration, and differentiation in the cerebral cortex. We describe the specific expression of ACE2 in neuronal precursors and migratory neuroblasts of the dentate gyrus in the hippocampus. This finding implies that SARS-CoV-2 infection during the fetal period may affect neuronal progenitor cells and alter the normal development of the brain region where memory engrams are generated. Thus, although vertical transmission of SARS-CoV-2 infection was reported in few cases, the massive infection rate of young people in terms of the new variants leads to the possibility of increasing the ratio of congenital infections and originating cognitive alterations, as well as neuronal circuit anomalies that may represent vulnerability to mental problems throughout life.

Nucleated red blood cells: unexpected orchestrators of fetal immunity

Abstract Red blood cells (RBCs) are not typically considered active immune mediators. This dogma stems from the fact that RBC precursors discard organelles as they mature, thus losing the ability to alter gene expression in response to stimuli. Intriguingly, nucleated RBCs (nRBCs) circulate in human fetuses and neonates. Due to evolutionary pressure for successful reproduction, circulation of nRBCs during pregnancy is likely important. However, the role of nRBCs in uteroremains unknown. To define the role of human nRBCs, we queried single cell RNA-seq data and found that transcriptomics support nRBCs as putative immune mediators. Unexpectedly, we found that nRBCs express antigen processing &amp; presentation machinery. nRBCs constitutively express MHC II &amp; co-stimulatory molecules, hallmarks of specialized antigen-presenting cells. We further demonstrated that nRBCs internalize and cleave antigens. Currently, we aim to determine if nRBCs present antigens to T cells and to characterize the elicited response. In addition, we found that nRBCs express pattern recognition receptors capable of detecting pathogens and initiating an antimicrobial response. We demonstrated that nRBCs respond to viral infection through upregulation of antiviral genes, interferons/interferon-stimulated genes, MHC I, and pro-inflammatory cytokines/chemokines. These data suggest a putative functionality for nRBCs in mediating antiviral immunity in utero. We are currently investigating antiviral functions of nRBCs. Together, our findings shed light on an unexpected orchestrator of fetal immunity. Knowledge of the fetal immune system has potential to help us understand health and disease during pregnancy, as a neonate, and likely every stage of life after. Supported by grants from NIH/NIDDK 5T32DK007780, NIH/NIGMS K12GM081259, Burroughs Wellcome Fund 2022 Next Gen Pregnancy Initiative Award

Report of an Experiment With a Fetal Ex-Utero Support System in Piglets.

Extreme prematurity remains one of the leading causes of neonatal death. An ex-utero treatment strategy that allows the fetus to develop beyond this period until capable of tolerating the transition to post-natal physiology would significantly impact the quality of care offered for this pre-viable patient population. In this study, we report our experience with an ex-utero support system for fetal pigswith the goal of support and survival for eight hours. Our experiment included two pigs at a gestational age equivalent to a 32-week human fetus. Following ultrasound assessment and delivery via hysterotomy, the fetuses were transferred to a 40 L glass aquarium filled with warmed lactated Ringer's solution and connected to an arteriovenous (AV) circuit that included a centrifugal pump and a pediatric oxygenator.Fetus 1 was successfully cannulated and survived for seven hours (expected maximum duration of eight hours). Fetus 2 died shortly after hysterotomy, secondary to failure at the cannulation stage. Our results suggest that ex-utero support of the premature fetal pig is feasible, contributing to a scarce body of evidence. However, further studies are needed before effectively translating an artificial placenta system into the clinical arena.

A CRISPR/Cas9-generated mutation in the zebrafish orthologue of PPP2R3B causes idiopathic scoliosis

Idiopathic scoliosis (IS) is the deformation and/or abnormal curvature of the spine that develops progressively after birth. It is a very common condition, affecting approximately 4% of the general population, yet the genetic and mechanistic causes of IS are poorly understood. Here, we focus on PPP2R3B, which encodes a protein phosphatase 2A regulatory subunit. We found that PPP2R3B is expressed at sites of chondrogenesis within human foetuses, including the vertebrae. We also demonstrated prominent expression in myotome and muscle fibres in human foetuses, and zebrafish embryos and adolescents. As there is no rodent orthologue of PPP2R3B, we used CRIPSR/Cas9-mediated gene-editing to generate a series of frameshift mutations in zebrafish ppp2r3b. Adolescent zebrafish that were homozygous for this mutation exhibited a fully penetrant kyphoscoliosis phenotype which became progressively worse over time, mirroring IS in humans. These defects were associated with reduced mineralisation of vertebrae, resembling osteoporosis. Electron microscopy demonstrated abnormal mitochondria adjacent to muscle fibres. In summary, we report a novel zebrafish model of IS and reduced bone mineral density. In future, it will be necessary to delineate the aetiology of these defects in relation to bone, muscle, neuronal and ependymal cilia function.