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WIREs Mechanisms of Disease Sep 2021The spinal cord is functionally and anatomically divided into ventrally derived motor circuits and dorsally derived somatosensory circuits. Sensory stimuli originating... (Review)
Review
The spinal cord is functionally and anatomically divided into ventrally derived motor circuits and dorsally derived somatosensory circuits. Sensory stimuli originating either at the periphery of the body, or internally, are relayed to the dorsal spinal cord where they are processed by distinct classes of sensory dorsal interneurons (dIs). dIs convey sensory information, such as pain, heat or itch, either to the brain, and/or to the motor circuits to initiate the appropriate response. They also regulate the intensity of sensory information and are the major target for the opioid analgesics. While the developmental mechanisms directing ventral and dorsal cell fates have been hypothesized to be similar, more recent research has suggested that dI fates are specified by novel mechanisms. In this review, we will discuss the molecular events that specify dorsal neuronal patterning in the spinal cord, thereby generating diverse dI identities. We will then discuss how this molecular understanding has led to the development of robust stem cell methods to derive multiple spinal cell types, including the dIs, and the implication of these studies for treating spinal cord injuries and neurodegenerative diseases. This article is categorized under: Neurological Diseases > Stem Cells and Development.
Topics: Cell Differentiation; Interneurons; Neurons; Spinal Cord; Touch
PubMed: 34730293
DOI: 10.1002/wsbm.1520 -
Development (Cambridge, England) Oct 2023Closed spinal dysraphisms are poorly understood malformations classified as neural tube (NT) defects. Several, including terminal myelocystocele, affect the distal...
Closed spinal dysraphisms are poorly understood malformations classified as neural tube (NT) defects. Several, including terminal myelocystocele, affect the distal spine. We have previously identified a NT closure-initiating point, Closure 5, in the distal spine of mice. Here, we document equivalent morphology of the caudal-most closing posterior neuropore (PNP) in mice and humans. Closure 5 forms in a region of active FGF signalling, and pharmacological FGF receptor blockade impairs its formation in cultured mouse embryos. Conditional genetic deletion of Fgfr1 in caudal embryonic tissues with Cdx2Cre diminishes neuroepithelial proliferation, impairs Closure 5 formation and delays PNP closure. After closure, the distal NT of Fgfr1-disrupted embryos dilates to form a fluid-filled sac overlying ventrally flattened spinal cord. This phenotype resembles terminal myelocystocele. Histological analysis reveals regional and progressive loss of SHH- and FOXA2-positive ventral NT domains, resulting in OLIG2 labelling of the ventral-most NT. The OLIG2 domain is also subsequently lost, eventually producing a NT that is entirely positive for the dorsal marker PAX3. Thus, a terminal myelocystocele-like phenotype can arise after completion of NT closure with localised spinal mis-patterning caused by disruption of FGFR1 signalling.
Topics: Animals; Humans; Mice; Neural Tube Defects; Phenotype; Spinal Cord; Spinal Dysraphism; Spine; Receptor, Fibroblast Growth Factor, Type 1
PubMed: 37756583
DOI: 10.1242/dev.202139 -
Frontiers in Surgery 2022Among the few studies that have examined the development of the anterior abdominal wall, several are based on incomplete "series", substituted in many cases by non-human...
PURPOSE
Among the few studies that have examined the development of the anterior abdominal wall, several are based on incomplete "series", substituted in many cases by non-human specimens.
MATERIAL AND METHODS
In total, 19 human embryos corresponding to Carnegie stages 15-23, 36 fetuses with estimated gestational ages ranging from 9 weeks to term, and eight neonates were included in this study. All specimens belong to the collection of the Department of Anatomy and Embryology at the Complutense University of Madrid.
RESULTS
The muscles of the anterior abdominal wall appear in the dorsal region at stages 15 and 16 (33-37 days). At stages 17 and 18 (41-44 days), this muscular mass grows ventrally and splits into two sheets: the external abdominal oblique muscle and the common mass of the internal abdominal oblique, and the transversus abdominis muscles, all of which end ventrally in the primitive condensation of the rectus abdominis. In embryos at stages 19 and 20 (48 days), the anterior abdominal wall continues to show an umbilical hernia in the amniotic cavity. However, a narrow neck is apparent for the first time and there is a wider anterior abdominal wall below the hernia made up of dense mesenchyme tissue without layers and showing the primordia of the umbilical canal. In embryos at stages 21, 22, and 23 (51-57 days), the abdominal muscles and aponeuroses cross the midline (linea alba) covering the rectus abdominis and pyramidalis muscles while the umbilical hernia has shrunk. In fetuses during the 9th and 10th weeks, the umbilical hernia becomes encircled by the rectus abdominis muscle, its aponeurosis, and the three layers of lateral abdominal muscles, which are more developed and covered by Camper's and Scarpa's fasciae. The inguinal canal has a course and relationships like those described in adults, with Hesselbach's ligament.
PubMed: 35433819
DOI: 10.3389/fsurg.2022.863679 -
Cureus Dec 2022Introduction A ventral hernia is defined as a non-inguinal, non-hiatal defect in the fascia of the abdominal wall. Approximately 350,000 ventral hernia procedures are...
Introduction A ventral hernia is defined as a non-inguinal, non-hiatal defect in the fascia of the abdominal wall. Approximately 350,000 ventral hernia procedures are performed each year. Ventral hernia can have a negative impact on a person's quality of life and, in severe situations, lead to hospitalization and even death. Aim This study aimed to assess the knowledge of the general population living in the Al-Ahsa region regarding the risk factors of ventral hernia. Subjects and methods This is a cross-sectional study conducted among the general population living in the Al-Ahsa region of Saudi Arabia. A self-administered questionnaire was distributed among the population using an online platform. The questionnaire includes basic demographic characteristics (age, gender, and body mass index (BMI)) and a nine-item questionnaire to assess the knowledge of risk factors of ventral hernia. Results Of the 803 respondents involved, 42.1% were aged between 22 and 28 years old, and 44.4% were either overweight or obese. According to participants' knowledge, the most common risk factor of ventral hernia was heavy weight lifting (87.4%), and pregnancy and labor (64.1%). The overall mean knowledge score was 5.78 (standard deviation (SD): 2.68) out of 12 points. Nearly half (49.4%) were considered to have poor knowledge levels, 40.2% were considered to have moderate knowledge levels, and only 10.6% were considered to have good knowledge levels. Increased knowledge was seen more frequently in younger participants, males, and respondents with normal or underweight BMI. Conclusion The knowledge of the general population regarding the risk factors of ventral hernia was insufficient. Of all the population, male respondents who were younger and had a normal body mass index demonstrated a better understanding of the ventral hernia's risk factors compared to the rest of the subjects. Further research is needed to establish the knowledge of the general population regarding the risk factors of ventral hernia in our region.
PubMed: 36660536
DOI: 10.7759/cureus.32581 -
RMD Open Jan 2022To propose a data-driven definition for structural changes of sacroiliac (SI) joints in the context of axial spondyloarthritis (axSpA) imaging on a large collective of...
OBJECTIVES
To propose a data-driven definition for structural changes of sacroiliac (SI) joints in the context of axial spondyloarthritis (axSpA) imaging on a large collective of CT datasets.
METHODS
546 individuals (102 axSpA, 80 non-axSpA low back pain and 364 controls without back pain) with SI joint CTs were evaluated for erosions, sclerosis and ankylosis using a structured scoring system. Lesion frequencies and spatial distribution were compared between groups. Diagnostic performance (sensitivity (SE), specificity (SP), positive predictive values, negative predictive values and positive and negative likelihood ratios) was calculated for different combinations of imaging findings. Clinical diagnosis served as standard of reference.
RESULTS
Ankylosis and/or erosions of the middle and dorsal joint portions yielded the best diagnostic performance with SE 67.6% and SP 96.3%. Inclusion of ventral erosions and sclerosis resulted in lower diagnostic performance with SE 71.2%/SP 92.5% and SE 70.6%/SP 90.0%, respectively.
CONCLUSIONS
Sclerosis and ventrally located erosions of SI joints have lower specificity on CT of the SI joint in the context of axSpA imaging. Ankylosis and/or erosions of the middle and dorsal joint portions show a strong diagnostic performance and are appropriate markers of a positive SI joint by CT.
Topics: Humans; Magnetic Resonance Imaging; Sacroiliac Joint; Sacroiliitis; Spondylarthritis; Tomography, X-Ray Computed
PubMed: 35064092
DOI: 10.1136/rmdopen-2021-001939 -
The Permanente Journal 2018With the incidence of ventral hernias increasing, surgeons are faced with greater complexity in dealing with these conditions. Proper knowledge of the history and the... (Review)
Review
With the incidence of ventral hernias increasing, surgeons are faced with greater complexity in dealing with these conditions. Proper knowledge of the history and the advancements made in managing complex ventral hernias will enhance surgical results. This review article highlights the literature regarding complex ventral hernias, including a shift from a focus that stressed surgical technique toward a multimodal approach, which involves optimization and identification of suboptimal characteristics.
Topics: Hernia, Ventral; Humans; Postoperative Care; Surgical Procedures, Operative; Tomography, X-Ray Computed
PubMed: 29272245
DOI: 10.7812/TPP/17-015 -
Fluids and Barriers of the CNS Jan 2023Detecting changes in pulsatile cerebrospinal fluid (CSF) flow may assist clinical management decisions, but spinal CSF flow is relatively understudied. Traumatic spinal...
BACKGROUND
Detecting changes in pulsatile cerebrospinal fluid (CSF) flow may assist clinical management decisions, but spinal CSF flow is relatively understudied. Traumatic spinal cord injuries (SCI) often cause spinal cord swelling and subarachnoid space (SAS) obstruction, potentially causing pulsatile CSF flow changes. Pigs are emerging as a favoured large animal SCI model; therefore, the aim of this study was to characterise CSF flow along the healthy pig spine.
METHODS
Phase-contrast magnetic resonance images (PC-MRI), retrospectively cardiac gated, were acquired for fourteen laterally recumbent, anaesthetised and ventilated, female domestic pigs (22-29 kg). Axial images were obtained at C2/C3, T8/T9, T11/T12 and L1/L2. Dorsal and ventral SAS regions of interest (ROI) were manually segmented. CSF flow and velocity were determined throughout a cardiac cycle. Linear mixed-effects models, with post-hoc comparisons, were used to identify differences in peak systolic/diastolic flow, and maximum velocity (cranial/caudal), across spinal levels and dorsal/ventral SAS. Velocity wave speed from C2/C3 to L1/L2 was calculated.
RESULTS
PC-MRI data were obtained for 11/14 animals. Pulsatile CSF flow was observed at all spinal levels. Peak systolic flow was greater at C2/C3 (dorsal: - 0.32 ± 0.14 mL/s, ventral: - 0.15 ± 0.13 mL/s) than T8/T9 dorsally (- 0.04 ± 0.03 mL/s; p < 0.001), but not different ventrally (- 0.08 ± 0.08 mL/s; p = 0.275), and no difference between thoracolumbar levels (p > 0.05). Peak diastolic flow was greater at C2/C3 (0.29 ± 0.08 mL/s) compared to T8/T9 (0.03 ± 0.03 mL/s, p < 0.001) dorsally, but not different ventrally (p = 1.000). Cranial and caudal maximum velocity at C2/C3 were greater than thoracolumbar levels dorsally (p < 0.001), and T8/T9 and L1/L2 ventrally (p = 0.022). Diastolic velocity wave speed was 1.41 ± 0.39 m/s dorsally and 1.22 ± 0.21 m/s ventrally, and systolic velocity wave speed was 1.02 ± 0.25 m/s dorsally and 0.91 ± 0.22 m/s ventrally.
CONCLUSIONS
In anaesthetised and ventilated domestic pigs, spinal CSF has lower pulsatile flow and slower velocity wave propagation, compared to humans. This study provides baseline CSF flow at spinal levels relevant for future SCI research in this animal model.
Topics: Humans; Female; Swine; Animals; Retrospective Studies; Magnetic Resonance Imaging; Cerebrospinal Fluid Pressure; Spinal Cord; Sus scrofa; Cerebrospinal Fluid
PubMed: 36653870
DOI: 10.1186/s12987-022-00401-4 -
Differentiation; Research in Biological... 2018The urethra within the human penile shaft develops via (1) an "Opening Zipper" that facilitates distal canalization of the solid urethral plate to form a wide urethral...
The urethra within the human penile shaft develops via (1) an "Opening Zipper" that facilitates distal canalization of the solid urethral plate to form a wide urethral groove and (2) a "Closing Zipper" that facilitates fusion of the epithelial surfaces of the urethral folds. Herein, we extend our knowledge by describing formation of the human urethra within the glans penis as well as development of the prepuce. Forty-eight normal human fetal penile specimens were examined using scanning electron microscopy and optical projection tomography. Serial histologic sections were evaluated for morphology and immunohistochemical localization for epithelial differentiation markers: Cytokeratins 6, 7, 10, FoxA1, uroplakin and the androgen receptor. As the closing zipper completes fusion of the urethral folds within the penile shaft to form a tubular urethra (~ 13 weeks), canalization of the urethral plate continues in proximal to distal fashion into the glans penis to directly form the urethra within the glans without forming an open urethral groove. Initially, the urethral plate is attached ventrally to the epidermis via an epithelial seam, which is remodeled and eliminated, thus establishing mesenchymal confluence ventral to the glanular urethra. The morphogenetic remodeling involves the strategic expression of cytokeratin 7, FoxA1 and uroplakin in endodermal epithelial cells as the tubular glanular urethra forms. The most ventral epithelial cells of the urethral plate are pinched off from the glanular urethra and are reabsorbed into the epidermis ultimately losing expression of their markers, a process undoubtedly regulated by androgens. The prepuce initially forms on the dorsal aspect of the glans at approximately 12 weeks of gestation. After sequential proximal to distal remodeling of the ventral urethral plate along the ventral aspect of glans, the prepuce of epidermal origin fuses in the ventral midline.
Topics: Cell Differentiation; Endoderm; Epithelial Cells; Gene Expression Regulation, Developmental; Hepatocyte Nuclear Factor 3-alpha; Humans; Male; Morphogenesis; Penis; Receptors, Androgen; Urethra; Uroplakins
PubMed: 30245194
DOI: 10.1016/j.diff.2018.08.002 -
JNMA; Journal of the Nepal Medical... Feb 2024A Spigelian hernia is a hernia through the Spigelian fascia which are difficult to diagnose as they do not present with a subcutaneous swelling and can be dangerous as...
UNLABELLED
A Spigelian hernia is a hernia through the Spigelian fascia which are difficult to diagnose as they do not present with a subcutaneous swelling and can be dangerous as there is a high risk of incarceration. We report a case of a 51-year-old female who presented to our surgical unit with epigastric pain for 5 days. She was diagnosed with Spigelian hernia with esophagitis and antral gastritis with the help of a computed tomography scan and upper gastrointestinal endoscopy. The diagnosis was confirmed on diagnostic laparoscopy and transabdominal preperitoneal repair of the defect was performed using prolene mesh. Her post-operative period was uneventful. Spigelian hernias are rare and patients can present with atypical symptoms as in this case. Thus, imaging plays a vital role in diagnosis. Management is surgical and has good outcomes.
KEYWORDS
case reports; rectus abdominis; ventral hernia.
Topics: Female; Humans; Middle Aged; Hernia, Ventral; Laparoscopy; Fascia; Tomography, X-Ray Computed; Abdominal Pain
PubMed: 38409978
DOI: 10.31729/jnma.8440