Prenatal diagnosis of caudal regression with heterotaxy syndrome: "A mermaid with a broken heart".

Caudal regression syndrome (CRS) is a rare congenital malformation with varying degrees of early gestational developmental failure. It is characterized by agenesis of the sacrum and lumbar spine, with lower limb neurological deficit and accompanying deformities of the pelvis, lower extremities, genitourinary, and gastrointestinal systems. We report a case of CRS associated with rare complex congenital heart defect, that is, heterotaxy syndrome, diagnosed prenatally.

Absence of collagen IX accelerates hypertrophic differentiation in the embryonic mouse spine through a disturbance of the Ihh-PTHrP feedback loop.

Collagen IX (Col IX) is a component of the cartilage extracellular matrix and contributes to its structural integrity. Polymorphisms in the genes encoding the Col IX ɑ2- and ɑ3-chains are associated with early onset of disc degeneration. Col IX-deficient mice already display changes in the spine at the newborn stage and premature disc degeneration starting at 6 months of age. To determine the role of Col IX in early spine development and to identify molecular mechanisms underlying disc degeneration, the embryonic development of the spine was analyzed in Col IX -/- mice. Histological staining was used to show tissue morphology at different time points. Localization of extracellular matrix proteins as well as components of signaling pathways were analyzed by immunohistochemistry. Developing vertebral bodies of Col IX -/- mice were smaller and already appeared more compact at E12.5. At E15.5, vertebral bodies of Col IX -/- mice revealed an increased number of hypertrophic chondrocytes as well as enhanced staining for the terminal differentiation markers alkaline phosphatase and collagen X. This correlates with an imbalance in the Ihh-PTHrP signaling pathway at this time point, reflected by an increase of Ihh and a concomitant decrease of PTHrP expression. An accelerated hypertrophic differentiation caused by a disturbed Ihh-PTHrP signaling pathway may lead to a higher bone mineral density in the vertebral bodies of newborn Col IX -/- mice and, as a result, to the early onset of disc degeneration.

A comprehensive review of the sub-axial ligaments of the vertebral column: part II histology and embryology.

BACKGROUND: As important as the vertebral ligaments are in maintaining the integrity of the spinal column and protecting the contents of the spinal canal, a single detailed review of their histology and embryology is missing in the literature. METHODS: A literature search using online search engines was conducted. RESULTS: Single comprehensive reviews of the histology and embryology of the spinal ligaments are not found in the extant medical literature. CONCLUSIONS: This review will be useful to those who study or treat patients with pathology of the spine.

Reference ranges for vertebral body areas of the fetal lumbosacral spine on 3-dimensional sonography using volume contrast imaging with OmniView.

OBJECTIVES; The purpose of this study was to establish reference ranges for vertebral body areas of the fetal lumbosacral spine in the coronal plane on 3-dimensional sonography using volume contrast imaging with OmniView (GE Healthcare, Zipf, Austria). METHODS; An observational cross-sectional study was conducted on 576 healthy pregnant women at gestational ages of 20 weeks to 34 weeks 6 days. Volume contrast imaging with OmniView was used to measure the vertebral body areas (L1-L5, S1, and S2) by positioning a curved line along the fetal lumbosacral spine. To create reference ranges, first- and second-degree linear regression models adjusted using residual analysis and the coefficient of determination (R(2)) were created. To assess reproducibility, two examiners evaluated 40 random volumes using the intraclass correlation coefficient. RESULTS; The mean areas of the vertebral bodies were 102.72 (range, 25-254), 107.29 (range, 30-245), 105.10 (range, 31-231), 99.09 (range, 31-211), 87.74 (range, 11-178), 65.80 (range, 18-161), and 46.54 (range, 12-129) mm(2) for L1, L2, L3, L4, L5, S1, and S2, respectively. In the intraobserver and interobserver reproducibility assessments, intraclass correlation coefficients of greater than 0.80 were found for all fetal vertebral body areas. CONCLUSIONS; Reference values for fetal lumbosacral spine vertebral body areas were determined by 3-dimensional sonography using volume contrast imaging with OmniView, and they were shown to be reproducible.

Colocalization in vivo and association in vitro of perlecan and elastin.

We have colocalized elastin and fibrillin-1 with perlecan in extracellular matrix of tensional and weight-bearing connective tissues. Elastin and fibrillin-1 were identified as prominent components of paraspinal blood vessels, and posterior longitudinal ligament in the human fetal spine and outer annulus fibrosus of the fetal intervertebral disc. We also colocalized perlecan with a synovial elastic basal lamina, where the attached synovial cells were observed to produce perlecan. Elastin, fibrillin-1 and perlecan were co-localized in the intima and media of small blood vessels in the synovium and in human fetal paraspinal blood vessels. Elastic fibers were observed at the insertion point of the anterior cruciate ligament to bone in the ovine stifle joint where they colocalized with perlecan. Elastin has not previously been reported to be spatially associated with perlecan in these tissues. Interactions between the tropoelastin and perlecan heparan sulfate chains were demonstrated using quartz crystal microbalance with dissipation solid phase binding studies. Electrostatic interactions through the heparan sulfate chains of perlecan and core protein mediated the interactions with tropoelastin, and were both important in the coacervation of tropoelastin and deposition of elastin onto perlecan immobilized on the chip surface. This may help us to understand the interactions which are expected to occur in vivo between the tropoelastin and perlecan to facilitate the deposition of elastin and formation of elastic microfibrils in situ and would be consistent with the observed distributions of these components in a number of connective tissues.

Prenatal evaluation of the position of the fetal conus medullaris.

OBJECTIVES: To determine the position of the fetal conus medullaris during pregnancy in relation to the last vertebral body and to examine its use in detecting skin-covered spinal dysraphism. METHODS: This was a retrospective study involving 300 consecutive ultrasound examinations between 15 weeks of gestation and term. Two operators independently assessed images of the spine to determine whether the conus medullaris and the last vertebral body could be visualized in a single image in a midsagittal plane. The distance between these two landmarks (the conus distance) was measured twice by both operators who were not aware of any previous measurements. Intra- and interobserver variability was assessed by 95% limits of agreement. Linear regression analysis was used to determine the relevant contributors to the conus distance and a normal range was computed based on the best-fit model. The normal results were compared with five cases of prenatally detected skin-covered spinal dysraphism. RESULTS: In 84.7% of the 300 cases, both operators were able to visualize the conus medullaris and the last vertebral body. Ninety-five percent limits of agreement for the intraobserver variability in measurement of conus distance were ± 1.9 mm. For the interobserver variability, they were - 3.7 and 2.5 mm. We found a linear relationship between conus distance and gestational age, biparietal diameter and abdominal circumference. The strongest relationship was observed for femur length (conus distance = - 8.2 + femur length (mm)). In the five abnormal cases, conus distance was well below the 5(th) percentile. CONCLUSIONS: Determination of conus distance allows for an objective and feasible assessment of the conus medullaris position. This parameter promises to be useful in the prenatal detection of skin-covered spinal dysraphism.

Contribution of the anterior longitudinal ligament to ossification and growth of the vertebral body: an immunohistochemical study using the human fetal lumbar vertebrae.

Using 15 mid-term human fetuses, we examined the role of the spine anterior and posterior longitudinal ligaments (ALL, PLL) in ossification of the lumbar vertebral body. By 18 weeks, a pair of calcified tissue or cortical walls had developed on the anterior and posterior sides of the ossification center. These calcified cortical walls were more highly eosinophilic than trabecular or woven bone in the ossification center. Vimentin-positive osteoblasts were arranged in line along the outer surface of the walls. However, few CD68-positive osteoclasts were evident around the walls, suggesting that the calcification in the walls was similar to periosteal ossification. The anterior cortical wall was connected tightly with the ALL by fiber bundles, but the posterior wall was separated from the PLL by the basivertebral (central) vein and loose tissues. Notably, by 30 weeks, the anterior cortical wall had become attached to and incorporated into the ALL. Thus, the ALL seemed to act as an active periosteum for ossification. Although our materials were limited in number and stage, we hypothesized that, in contrast to the PLL, the mature anterior cortical wall corresponds to a calcified fibrocartilage adjacent to the ALL and forms a bone-ligament interface maintaining an ossification potential.

Size and location of the kidneys during the fetal period.

PURPOSE: The aim of this study was to determine the morphometric development and location of the kidneys during the fetal period. METHODS: Three hundred and forty-four fetal kidneys, obtained from 172 human fetuses and aged between 9 and 40 weeks, were used in this study. Fetuses were divided into four groups according to the gestational weeks: first trimester, second trimester, third trimester, and full-term gestation. First, the anterior abdominal wall was dissected. Topographic localization of the kidneys in the abdominal cavity was then assessed. The distance between the inferior pole of the kidney and iliac crest was measured. The vertebral levels of the superior and the inferior poles and relations to ribs of the kidneys were determined. The distances between hilum of the kidneys and inferior vena cava, abdominal aorta, and midline of the vertebral column were determined. The dimensions (width, length, and thickness), weight, and volume of kidneys were measured. RESULTS: The results showed that the distance between the inferior poles of the kidneys and the iliac crest increases with gestational age. The vertebral levels of the superior and inferior poles of the kidneys increased during the fetal period. The level of the left kidney was higher than the level of the right kidney in the fetal period. The posterior surface relations to the ribs showed certain ascendance during gestation, corresponding to vertebral levels. However, fetal kidneys do not reach the same level as adults at full term. The kidneys move farther apart from the midline of the body during the fetal period. The dimensions, weight, and volume of the kidneys increased with gestational age during the fetal period. The ratio between kidney weights and fetal body weights were determined, and we observed that the ratio decreased during the fetal period. There were no sex or laterality differences in any parameter. CONCLUSIONS: The morphometric parameters and the location of the fetal kidneys were determined by the present study. This will also contribute to imaging of fetal kidneys and detection of kidney abnormalities in the intrauterine period. We hope that the present results can provide some useful findings for radiological (ultrasound and MR) studies.

Differentiation of the nuclear groups in the posterior horn of the human embryonic spinal cord.

The formation of nuclear groups in the posterior horns of the human embryonic spinal cord was traced in serial sections of embryos of developmental stages 13 to 23 (32 to 56 postovulatory days). The following observations, new for the human, are presented: 1. The differentiation of the neural tube into 3 zones (germinal, mantle and marginal) is detected in the middle of the 5(th) week. 2. The primordia of the posterior horns are marked at stage 14 (33 days). 3. In the middle of the 7(th) week the nucleus proprius and substantia gelatinosa are discerned. 4. Differentiation of the nuclei within the posterior horns proceeds in the ventrodorsal and rostrocaudal gradients.

Restricted patterns of Hoxd10 and Hoxd11 set segmental differences in motoneuron subtype complement in the lumbosacral spinal cord.

During normal vertebrate development, Hoxd10 and Hoxd11 are expressed by differentiating motoneurons in restricted patterns along the rostrocaudal axis of the lumbosacral (LS) spinal cord. To assess the roles of these genes in the attainment of motoneuron subtypes characteristic of LS subdomains, we examined subtype complement after overexpression of Hoxd10 or Hoxd11 in the embryonic chick LS cord and in a Hoxd10 loss-of-function mouse embryo. Data presented here provide evidence that Hoxd10 defines the position of the lateral motor column (LMC) as a whole and, in rostral LS segments, specifically promotes the development of motoneurons of the lateral subdivision of the lateral motor column (LMCl). In contrast, Hoxd11 appears to impart a caudal and medial LMC (LMCm) identity to some motoneurons and molecular profiles suggestive of a suppression of LMC development in others. We also provide evidence that Hoxd11 suppresses the expression of Hoxd10 and the retinoic acid synthetic enzyme, retinaldehyde dehydrogenase 2 (RALDH2). In a normal chick embryo, Hoxd10 and RALDH2 are expressed throughout the LS region at early stages of motoneuron differentiation but their levels decline in Hoxd11-expressing caudal LS segments that ultimately contain few LMCl motoneurons. We hypothesize that one of the roles played by Hoxd11 is to modulate Hoxd10 and local retinoic acid levels and thus, perhaps define the caudal boundaries of the LMC and its subtype complement.

Sonographic evaluation of the fetal conus medullaris at 20 to 24 weeks' gestation.

OBJECTIVE: To determine the normal level of the conus medullaris (CM) of the spinal cord of normal fetuses at 20 to 24 weeks' gestation using abdominal sonography. METHODS: Using a 4 to 8 MHz ultrasound abdominal transducer, CM was imaged in the midsagittal plane with the fetal spine facing toward the transducer. The CM ending level was located by counting the vertebrae caudal starting at T12, which was identified by lowest fetal rib. The CM locations were defined according to their positions relative to the vertebrae. RESULTS: One hundred and ten consecutive pregnant women were included in the study. The CM was clearly demonstrated in 78 (71%) of these cases. Most of the scanned fetuses had the CM ending height adjacent to vertebrae L2, L2-3 inter-space and L3 (73/78, 93%). The L1-2, L2, L2-3, and L3 vertebral groups did not differ in mean gestational weeks, maternal age, or fetal gender. CONCLUSION: The level of the CM can be determined at 20 to 24 weeks' gestation in about 70% of fetuses. Most of the scanned fetuses had the CM ending height adjacent to vertebrae L2, L2-3 vertebral space, and L3 (73/78, 93%). When detected lower than the third lumbar vertebra it should prompt prenatal and postnatal surveillance.

Occurrence and fate of fetal lumbar rib induced by Scutellariae radix in rats.

BACKGROUND: This study was conducted to evaluate the occurrence and fate of fetal lumbar rib induced by Scutellariae radix (SR) in rats. METHODS: Water extracts of SR were orally administered to pregnant rats from day 7 to day 17 of gestation at a dose of 186 mg/kg/day, equivalent to 25 g/kg of starting material, representing a 100-fold increase over typical human intake level. RESULTS: The incidence of fetal lumbar rib in the SR-treated group was increased on gestational day 20 and then decreased on postnatal day 50. The weight of fetuses in the SR-treated group tended to be less than that in the control group. Alkaline phosphatase in SR-treated dams was increased on gestational day 20, but was decreased on postnatal day 50. There were no significant differences between the vehicle control and SR-treated groups in maternal body weight, embryological, histopathological, hematological, and serum biochemical changes. CONCLUSIONS: The present data suggest that the appearance of lumbar rib induced by SR is a transient fetal variation rather than teratogenicity or maternal toxicity.

Immunohistochemical identification of notochordal markers in cells in the aging human lumbar intervertebral disc.

The fate of notochord cells during disc development and aging is still a subject of debate. Cells with the typical notochordal morphology disappear from the disc within the first decade of life. However, the pure morphologic differentiation of notochordal from non-notochordal disc cells can be difficult, prompting the use of cellular markers. Previous reports on these notochordal cell markers only explored the occurrence in young age groups without considering changes during disc degeneration. The aim of this study, therefore, was to investigate presence, localization, and abundance of cells expressing notochordal cell markers in human lumbar discs during disc development and degeneration. Based on pilot studies, cytokeratins CK-8, -18 and -19 as well as Galectin-3 were chosen from a broad panel of potential notochordal cell markers and used for immunohistochemical staining of 30 human lumbar autopsy samples (0-86 years) and 38 human surgical disc samples (26-69 years). In the autopsy group, 80% of fetal to adolescent discs (0-17 years) and 100% of young adult discs (18-30 years) contained many cells with positive labeling. These cells were strongly clustered and nearly exclusively located in areas with granular changes (or other matrix defects), showing predominantly a chondrocytic morphology as well as (in a much lesser extent) a fibrocytic phenotype. In mature discs (31-60 years) and elderly discs (≥ 60 years) only 25 and 22-33%, respectively, contained few stained nuclear cells, mostly associated with matrix defects. In the surgical group, only 16% of samples from young adults (≤ 47 years) exhibited positively labeled cells whereas mature to old surgical discs (>47 years) contained no labeled cells. This is the first study describing the presence and temporo-spatial localization of cells expressing notochordal cell markers in human lumbar intervertebral discs of all ages and variable degree of disc degeneration. Our findings indicate that cells with a (immunohistochemically) notochord-like phenotype are present in a considerable fraction of adult lumbar intervertebral discs. The presence of these cells is associated with distinct features of (early) age-related disc degeneration, particularly with granular matrix changes.

Formation of the vertebral arches of the cervical, thoracic and lumbar vertebrae in early human foetuses.

Fusion of the neural arches was studied in 6 serially sectioned human foetuses aged 9 and 10 weeks. In foetuses of 9 weeks, the completion of arches was observed in the cervical, upper thoracic, and middle thoracic regions of the vertebral column. During the 10th week of development, fusion of neural processes progresses in the lower thoracic and upper three lumbar vertebrae.

Prenatal diagnosis of fetal multiple hemivertebrae: the importance of 3D ultrasound assessment.

We herein present a case of fetal multiple hemivertebrae detected at antenatal sonography. The use of the 3 D technology supported by a new contrast enhancement rendering algorithm (Crystal Vue) has allowed the accurate prenatal classification of the defect, confirmed at follow up, that would have been difficult to define by 2 D only.

Role of radial glia in transformation of the primitive lumen to the central canal in the developing rat spinal cord.

In the last quarter of the embryonic development of rat and shortly after a termination of neurogenesis, the transformation of the spinal cord primitive lumen (pL) to the central canal (CC) occurs. In this work, we show that this phenomenon is not an insignificant event but it is directly associated with the processes of gliogenesis. Using a light microscopy and immunohistochemistry, we monitored the development of the rat embryonic spinal cord from the end of the neurogenesis on the embryonic day 17 until the maturation of the spinal cord during the first postnatal weeks. Our observations demonstrate the importance of the transformation of the pL to the CC and its connection with gliogenesis, and the mechanism of this transformation is proposed. It is found that a segregation of the glutamate transporter (GLAST) immunopositive cells from the alar plates and transformation of the radial glial cells to the fibrous and protoplasmic astrocytes play presumably a key role in the diminution of the ventricular zone. Results indicate that the very transformation and migration of the radial glial cells during gliogenesis could result in a transformation of the pL to the CC.

Lumbosacral lordosis in fetal spine: genetic or mechanic parameter.

Many believe that the fetus spine had only one curvature from cranial to caudal which is a global kyphosis and that the lumbosacral lordosis appears with the erect posture. They agree that the sacrum of Homo sapiens is not positioned posteriorly at birth and that it is during the first few years that the sacrum, in humans, moves dorsally in relation with the progressive acquisition of erect posture and the ontogeny of bipedal locomotion. Nevertheless, there is no biometric study assessing these parameters in vivo in utero during the fetal life. Cross-sectional biometric study of the lumbosacral junction of the spine in in utero fetuses was to document the presence of a lumbosacral lordosis in the fetal population in utero long before standing and walking and its change during growth. Forty-five MRIs (magnetic resonance imaging) of fetuses aged of 23-40 weeks of gestation were analyzed. The measurements were performed on computerized MRI DICOM images using a professional software to calculate the curvature and radius of the lumbosacral junction. The presence or absence of visual lumbosacral lordosis was noted for each case. Correlation tests were performed in order to disclose a correlation between the gestational age and the curvature calculated. A test was considered significant for P < 0.01. There were 14 males, 17 females and 14 undetermined. All the curves (100%) showed mathematically the presence of a lordosis in the lumbosacral region. The visual lumbosacral lordosis was present in 60% of cases. The measurement of the lumbosacral curvature varies between -0.133 and -0.033 mm(-1) and a mean of -0.054 mm(-1) with a corresponding radius ranging from -7 to -303 mm with a mean of -18.7 mm. The statistical analysis showed no correlation between the gestational age and the lumbosacral curvature (R (2) = 0.11). The hypothesis of increased lumbosacral lordosis with gestational age is rejected. It is difficult to accurately determine the role played separately by genetics and by erect posture. A visual lumbosacral lordosis was noted in 60% of cases with mean radius of -18.6691 mm. This lordosis was not correlated statistically to gestational age which means that it is not related to growth and might be genetically determined. Mechanical factors may play a major role in the determination of the shape of the growing pelvis. One can ask if the pelvis morphology is genetically determined or if it is mechanically determined under muscular and ligamentous stresses. This study shows that the sacrum of human fetuses is oriented posteriorly mathematically in 100% of cases, and in 60% of cases based on the morphologic appearance of the lumbosacral junction. So beside the effect of progressive acquisition of erect posture and bipedalism in determining the formation of lumbosacral angle, we believe that genetics play an important role in the formation of the lumbosacral angle.

The Embryonic Ascent of the Kidney Revisited.

Although the embryonic kidney's ascent is well established, the intermediate morphological changes that occur during the process are unclear. To evaluate the morphological events that accompany the kidney's ascent, we examined serial sagittal sections from 24 embryos at 5-7 weeks gestation. Six specimens had bilaterally ascending kidneys that were between the levels of the second to fifth lumbar vertebrae, and each kidney had a primitive renal cortex surrounding clusters of ampullae, which branched from the pelvis, and a dense tissue band that connected the renal cortex with the embryonic adrenal cortex or celiac ganglia, and there was no adipose capsule or renal artery. The tissue band contained abundant nerve twigs from the major splanchnic nerve; thus, it was conceivable that it was sufficiently rigid to support the length of the retroperitoneal tissue mass that included the embryonic adrenal cortex, celiac ganglia, and kidney. The lumbar vertebral body's height was much shorter than that of the ascending kidney. However, the lower vertebral column's curvature was often maintained, even when the kidneys had ascended. Therefore, vertebral column straightening was not the only factor required to drive the ascent. Together with the growth of the thorax and liver, the adrenal cortex, ganglia, and kidney appeared to change simultaneously at a position relative to the vertebrae. The renal artery established a connection to the renal cortex after the ascent. Evaluations of frontal sections from five additional specimens suggested that from its initial position, the kidney extended upwards between bilateral umbilical arteries. Anat Rec, 302:278-287, 2019. © 2018 The Authors. The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology published by Wiley Periodicals, Inc. on behalf of Wiley-Liss, Inc.

Cyclooxygenase inhibitors affect bone mineralization in rat fetuses.

Intrauterine growth retardation, increased incidence of developmental variations, lack of cartilage and joint developmental side effects were previously reported for nonselective (ibuprofen, piroxicam, tolmetin) and selective (DFU) cyclooxygenase (COX)-2 inhibitors, also known as nonsteroidal anti-inflammatory drugs. The aim of the present study was to evaluate the lumbar vertebra mineralization in fetuses prenatally exposed to COX inhibitors. All the tested compounds were administered intragastrically to pregnant rats from gestational days 8 to 21. Fetuses were delivered on gestational day 21, and after digital radiological examination were double-stained with alcian blue and alizarin. Decrease of alizarin staining, as a qualitative sign of mineralization, was significantly greater in groups exposed to the highest doses of the nonselective COX inhibitors. Decrease of vertebra mineralization in drug-exposed groups was also revealed using quantitative radiological analysis. However, significant differences were noted only for the fifth and sixth lumbar vertebrae in the group exposed to the highest dose of tolmetin. Strong influence of the total protein level in maternal sera on the fetal bone optic density was found. It should be stressed that unlike DFU, the examined nonselective COX inhibitors decreased fetal bone mineralization when administered in high maternal toxic doses. Moreover, maternal health status determined fetal bone mineralization.

Prenatal diagnosis of partial lumbar asoma by two- and three-dimensional ultrasound and computed tomography: embryological aspects and perinatal management.

Asoma is an unusual type of hemivertebra distinct from lateral hemivertebra in its underlying mechanisms, its rarity, its often isolated nature and the high risk of it causing medullary compression. We report a case of isolated partial agenesis of a vertebral body (asoma) diagnosed at 23 weeks' gestation by ultrasonography, in a fetus showing hyperkyphosis with vertebral canal disruption. The diagnosis was established using ultrasound and computed tomography, which allowed measurement of the angle of kyphosis and helped in the determination of the postnatal orthopedic prognosis. In our patient, prenatal diagnosis of asoma facilitated optimization of postnatal management and reduced the neonate's risk of developing paralysis. The main anatomical parameters in the determination of the orthopedic risk are the level of the anomaly, the angle of kyphosis and the degree of vertebral canal disruption.