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Acta Neurochirurgica Jan 2023Surgical exposure of lower cervical and upper thoracic intradural extramedullary lesions located along the ventral medulla are among the most complexes to address in...
BACKGROUND
Surgical exposure of lower cervical and upper thoracic intradural extramedullary lesions located along the ventral medulla are among the most complexes to address in spinal surgery, and their surgical removal carries a high risk.
METHODS
We describe the surgical steps of a posterolateral transpedicular approach for resection of an intradural extramedullary lesion located anterolaterally at C7-T1 level.
CONCLUSIONS
A posterolateral transpedicular approach is a safe and efficient surgical corridor to explore the ventral spinal cord and to have a direct access to lower cervical-upper thoracic lesions without the extensive manipulation of the spinal cord and the spine instability.
Topics: Humans; Spinal Cord Diseases; Neurosurgical Procedures; Spinal Diseases; Spinal Cord Neoplasms; Magnetic Resonance Imaging
PubMed: 36414756
DOI: 10.1007/s00701-022-05424-2 -
Journal of Anatomy Aug 2004Two embryological fates for cells of the neural tube are well established. Cells from the dorsal part of the developing neural tube emigrate and become neural crest... (Review)
Review
Two embryological fates for cells of the neural tube are well established. Cells from the dorsal part of the developing neural tube emigrate and become neural crest cells, which in turn contribute to the development of the peripheral nervous system and a variety of non-neural structures. Other neural tube cells form the neurons and glial cells of the central nervous system (CNS). This has led to the neural crest being treated as the sole neural tube-derived emigrating cell population, with the remaining neural tube cells assumed to be restricted to forming the CNS. However, this restriction has not been tested fully. Our investigations of chick, quail and duck embryos utilizing a variety of different labelling techniques (DiI, LacZ, GFP and quail chimera) demonstrate the existence of a second neural tube-derived emigrating cell population. These cells originate from the ventral part of the cranial neural tube, emigrate at the exit/entry site of the cranial nerves, migrate in association with the nerves and populate their target tissues. On the basis of its site of origin and route of migration we have named this cell population the ventrally emigrating neural tube (VENT) cells. VENT cells also differ from neural crest cells in that they emigrate considerably after the emigration of neural crest cells, and lack expression of the neural crest cell antigen HNK-1. VENT cells are multipotent, differentiating into cell types belonging to all four basic tissues in the body: the nerve, muscle, connective and epithelium. Thus, the neural tube provides at least two cell populations--neural crest and VENT cells--that contribute to the development of the peripheral nervous system and various non-neural structures. This review describes the origin of the idea of VENT cells, and discusses evidence for their existence and subsequent fates.
Topics: Animals; CD57 Antigens; Cell Differentiation; Cell Movement; Chick Embryo; Connective Tissue; Cranial Nerves; Ducks; Epithelial Cells; Muscle, Skeletal; Neural Crest; Neuroglia; Neurons; Quail
PubMed: 15291792
DOI: 10.1111/j.0021-8782.2004.00319.x -
Scientific Reports Dec 2019We describe three-dimensionally preserved feathers in mid-Cretaceous Burmese amber that share macro-morphological similarities (e.g., proportionally wide rachis with a...
We describe three-dimensionally preserved feathers in mid-Cretaceous Burmese amber that share macro-morphological similarities (e.g., proportionally wide rachis with a "medial stripe") with lithic, two-dimensionally preserved rachis-dominated feathers, first recognized in the Jehol Biota. These feathers in amber reveal a unique ventrally concave and dorsoventrally thin rachis, and a dorsal groove (sometimes pigmented) that we identify as the "medial stripe" visible in many rachis-dominated rectrices of Mesozoic birds. The distally pennaceous portion of these feathers shows differentiated proximal and distal barbules, the latter with hooklets forming interlocking barbs. Micro-CT scans and transverse sections demonstrate the absence of histodifferentiated cortex and medullary pith of the rachis and barb rami. The highly differentiated barbules combined with the lack of obvious histodifferentiation of the barb rami or rachis suggests that these feathers could have been formed without the full suite and developmental interplay of intermediate filament alpha keratins and corneous beta-proteins that is employed in the cornification process of modern feathers. This study thus highlights how the development of these feathers might have differed from that of their modern counterparts, namely in the morphogenesis of the ventral components of the rachis and barb rami. We suggest that the concave ventral surface of the rachis of these Cretaceous feathers is not homologous with the ventral groove of modern rachises. Our study of these Burmese feathers also confirms previous claims, based on two-dimensional fossils, that they correspond to an extinct morphotype and it cautions about the common practice of extrapolating developmental aspects (and mechanical attributes) of modern feathers to those of stem birds (and their dinosaurian outgroups) because the latter need not to have developed through identical pathways.
PubMed: 31792276
DOI: 10.1038/s41598-019-54429-y -
Developmental Dynamics : An Official... Sep 2020Neural crest cells (NCCs) delaminate from the neural tube (NT) and migrate ventrally to generate the trunk peripheral nervous system (PNS). Although several signaling...
BACKGROUND
Neural crest cells (NCCs) delaminate from the neural tube (NT) and migrate ventrally to generate the trunk peripheral nervous system (PNS). Although several signaling pathways have been identified that steer NCCs once they are on their ventral trajectory, no molecules have been identified that are required for the initial migration between the NT and the dorsal root ganglion. Given the critical role of fibroblast growth factor (FGF) signaling in embryogenesis, we investigated its function in this initial migration.
RESULTS
FGFR1 signaling is required for the migration of newly delaminated NCCs onto the ventral pathway. Live imaging of migrating NCCs revealed that inhibition of FGFR1 signaling caused the dorsally stalled NCCs to lose their dorsal/ventral oriented polarity and instead adopt a rounded morphology while dynamically extending filopodia. FGF8, an FGFR1 ligand, increased motility of NCCs away from the NT by acting chemokinetically. Finally, we provide evidence that inhibition of FGFR1-mediated chemokinesis is partially rescued by increasing Akt signaling, inhibiting RhoA, and activation of N-cadherin signaling.
CONCLUSION
These data support a model in which NCCs are stimulated chemokinetically by FGF:FGFR1 signaling, and that this activation positions and orients NCCs on their ventral migratory route-a process that is essential for patterning the trunk PNS.
Topics: Animals; Cell Movement; Chemokines; Fibroblast Growth Factors; Ganglia, Spinal; Mice; Neural Crest; Receptor, Fibroblast Growth Factor, Type 1; Signal Transduction
PubMed: 32390246
DOI: 10.1002/dvdy.190 -
Frontiers in Cell and Developmental... 2021Myeloid cell leukemia-1 (Mcl-1), an anti-apoptotic Bcl-2 protein, regulates neural precursor cell (NPC) survival in both the developing and adult mammalian nervous...
Myeloid cell leukemia-1 (Mcl-1), an anti-apoptotic Bcl-2 protein, regulates neural precursor cell (NPC) survival in both the developing and adult mammalian nervous system. It is unclear when during the neurogenic period Mcl-1 becomes necessary for NPC survival and whether Bax is the sole pro-apoptotic target of Mcl-1. To address these questions, we used the nervous system-specific Nestin-Cre Mcl-1 conditional knockout mouse line (Mcl-1 CKO) to assess the anti-apoptotic role of Mcl-1 in developmental neurogenesis. Loss of Mcl-1 resulted in a wave of apoptosis beginning in the brainstem and cervical spinal cord at embryonic day 9.5 (E9.5) and in the forebrain at E10.5. Apoptosis was first observed ventrally in each region and spread dorsally over time. Within the spinal cord, apoptosis also spread in a rostral to caudal direction following the path of differentiation. Breeding the Mcl-1 CKO mouse with the Bax null mouse rescued the majority of NPC from apoptosis except in the dorsomedial brainstem and ventral thoracic spinal cord where only 50% were rescued. This demonstrates that Mcl-1 promotes NPC survival primarily by inhibiting the activation of Bax, but that Bax is not the sole pro-apoptotic target of Mcl-1 during embryonic neurogenesis. Interestingly, although co-deletion of Bax rescued the majority of NPC apoptosis, it resulted in embryonic lethality at E13, whereas conditional deletion of both Mcl-1 and Bax rescued embryonic lethality. In summary, this study demonstrates the widespread dependency on Mcl-1 during nervous system development.
PubMed: 33959612
DOI: 10.3389/fcell.2021.659531 -
Brain : a Journal of Neurology Mar 2015In humans, touching the skin is known to activate, among others, the contralateral primary somatosensory cortex on the postcentral gyrus together with the bilateral...
In humans, touching the skin is known to activate, among others, the contralateral primary somatosensory cortex on the postcentral gyrus together with the bilateral parietal operculum (i.e. the anatomical site of the secondary somatosensory cortex). But which brain regions beyond the postcentral gyrus specifically contribute to the perception of touch remains speculative. In this study we collected structural magnetic resonance imaging scans and neurological examination reports of patients with brain injuries or stroke in the left or right hemisphere, but not in the postcentral gyrus as the entry site of cortical somatosensory processing. Using voxel-based lesion-symptom mapping, we compared patients with impaired touch perception (i.e. hypoaesthesia) to patients without such touch impairments. Patients with hypoaesthesia as compared to control patients differed in one single brain cluster comprising the contralateral parietal operculum together with the anterior and posterior insular cortex, the putamen, as well as subcortical white matter connections reaching ventrally towards prefrontal structures. This finding confirms previous speculations on the 'ventral pathway of somatosensory perception' and causally links these brain structures to the perception of touch.
Topics: Adolescent; Adult; Aged; Brain Injuries; Brain Mapping; Female; Functional Laterality; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Middle Aged; Neural Pathways; Neurologic Examination; Perceptual Disorders; Somatosensory Cortex; Statistics, Nonparametric; Touch; Young Adult
PubMed: 25541190
DOI: 10.1093/brain/awu370 -
Neurologia Medico-chirurgica Oct 2023Surgery on spinal tumors becomes challenging when the tumor is ventral to the spinal cord. Conventionally, we approach it posteriorly through bilateral laminectomy and...
Surgery on spinal tumors becomes challenging when the tumor is ventral to the spinal cord. Conventionally, we approach it posteriorly through bilateral laminectomy and rotate the cord after sectioning the dentate ligament and nerve roots. However, manipulating the cord can be hazardous, and a long bilateral laminectomy can be invasive. Meanwhile, a narrow operative field and a limited lateral viewing angle in a unilateral approach constrained the surgeon. To overcome these problems, we previously reported a technique of modified unilateral approach where we incised the skin and the fascia horizontally and placed a pair of retractors longitudinally.The current article reports our experience applying this approach in 15 patients with ventrally located spinal tumors. The approach was performed on 10 schwannomas, 2 meningiomas, and 3 others. We evaluated paraspinal muscle atrophy on postoperative magnetic resonance imaging.The modified unilateral approach provided an excellent surgical field for removing ventrally located tumors. Gross total removal was achieved in 11 patients (92% of benign tumors). No neurological complications occurred except for one case of transient weakness. We encountered no wound-related late complications such as pain or deformity. The reduction of the cross-sectional area of the paraspinal muscles on the approach side (compared to the nonapproach side) was 0.93 (95% confidence interval: 0.72-1.06), indicating 7% atrophy (statistically nonsignificant, p = 0.48).We believe this simple technique can be useful for removing spinal tumors located ventral to the spinal cord.
Topics: Humans; Spinal Neoplasms; Meningeal Neoplasms; Spinal Cord Neoplasms; Meningioma; Laminectomy; Atrophy; Treatment Outcome
PubMed: 37495522
DOI: 10.2176/jns-nmc.2022-0330 -
Der Chirurg; Zeitschrift Fur Alle... Sep 2021Endoscopic management of umbilical and incisional hernias has adapted to the limitations of conventional laparoscopic instruments over the past 30 years. This includes... (Review)
Review
[Robotic hernia repair : Part II: Robotic primary ventral and incisional hernia repair (rv-TAPP and r-Rives or r-TARUP). Video report and results of a series of 118 patients].
Endoscopic management of umbilical and incisional hernias has adapted to the limitations of conventional laparoscopic instruments over the past 30 years. This includes the development of meshes for intraperitoneal placement (intraperitoneal onlay mesh, IPOM), with antiadhesive coatings; however, adhesions do occur in a significant proportion of these patients. Minimally invasive procedures result in fewer perioperative complications, but with a slightly higher recurrence rate. With the ergonomic resources of robotics, which offers angled instruments, it is now possible to implant meshes in a minimally invasively manner in different abdominal wall layers while achieving morphologic and functional reconstruction of the abdominal wall. This video article presents the treatment of ventral and incisional hernias with mesh implantation into the preperitoneal space (robot-assisted transabdominal preperitoneal ventral hernia repair, r‑ventral TAPP) as well as into the retrorectus space (r-Rives and robotic transabdominal retromuscular umbilical prosthetic repair, r‑TARUP, respectively). The results of a cohort study of 118 consecutive patients are presented and discussed with regard to the added value of the robotic technique in extraperitoneal mesh implantation and in the training of residents.
Topics: Amidines; Cohort Studies; Hernia, Ventral; Herniorrhaphy; Humans; Incisional Hernia; Laparoscopy; Robotics; Surgical Mesh
PubMed: 34255114
DOI: 10.1007/s00104-021-01450-5 -
NeuroImage Dec 2017The macaque monkey ventral intraparietal area (VIP) contains neurons with aligned visual-tactile receptive fields anchored to the face and upper body. Our previous fMRI...
The macaque monkey ventral intraparietal area (VIP) contains neurons with aligned visual-tactile receptive fields anchored to the face and upper body. Our previous fMRI studies using standard head coils found a human parietal face area (VIP+ complex; putative macaque VIP homologue) containing superimposed topological maps of the face and near-face visual space. Here, we construct high signal-to-noise surface coils and used phase-encoded air puffs and looming stimuli to map topological organization of the parietal face area at higher resolution. This area is consistently identified as a region extending between the superior postcentral sulcus and the upper bank of the anterior intraparietal sulcus (IPS), avoiding the fundus of IPS. Using smaller voxel sizes, our surface coils picked up strong fMRI signals in response to tactile and visual stimuli. By analyzing tactile and visual maps in our current and previous studies, we constructed a set of topological models illustrating commonalities and differences in map organization across subjects. The most consistent topological feature of the VIP+ complex is a central-anterior upper face (and upper visual field) representation adjoined by lower face (and lower visual field) representations ventrally (laterally) and/or dorsally (medially), potentially forming two subdivisions VIPv (ventral) and VIPd (dorsal). The lower visual field representations typically extend laterally into the anterior IPS to adjoin human area AIP, and medially to overlap with the parietal body areas at the superior parietal ridge. Significant individual variations are then illustrated to provide an accurate and comprehensive view of the topological organization of the parietal face area.
Topics: Adult; Brain Mapping; Face; Female; Humans; Magnetic Resonance Imaging; Male; Parietal Lobe; Young Adult
PubMed: 28889002
DOI: 10.1016/j.neuroimage.2017.09.004 -
EvoDevo Apr 2023Schizocardium karankawa sp. nov. has been collected from subtidal muds of the Laguna Madre, Texas, and the Mississippi coast, Gulf of Mexico. The Texas population is...
Schizocardium karankawa sp. nov. has been collected from subtidal muds of the Laguna Madre, Texas, and the Mississippi coast, Gulf of Mexico. The Texas population is reproductive from early February to mid-April. Gametes are liberated by a small incision in a gonad. Oocyte germinal vesicle breakdown is increased in the presence of sperm, and the highest fertilization success was in the artificial seawater Jamarin U. Manually dechorionated embryos develop normally. Development was asynchronous via a tornaria larva, metamorphosis and maintained to the juvenile worm 6 gill-pore stage. Phalloidin-labeled late-stage tornaria revealed retractor muscles that connect the pericardial sac with the apical tuft anteriorly, the oesophagus ventrally, and muscle cells of the early mesocoels. The muscle development of early juvenile worms began with dorso-lateral trunk muscles, lateral trunk bands, and sphincters around the gill pores and anus. Adult worms are characterized by a stomochord that bifurcates anteriorly into paired vermiform processes, gill bars that extend almost the entire dorsal to ventral branchial region resulting in a narrow ventral hypobranchial ridge, and an elaborate epibranchial organ with six zones of discrete cell types. The trunk has up to three rows of liver sacs, and lateral gonads. The acorn worm evo-devo model species Saccoglossus kowalevskii, Ptychodera flava, and Schizocardium californicum are phylogenetically distant with disparate life histories. S. karnakawa from S. californicum are phylogenetically close, and differences between them that become apparent as adult worms include the number of gill pores and hepatic sacs, and elaborations of the heart-kidney-stomochord complex. An important challenge for evolutionary developmental biology is to form links from phylogenetically distant and large-scale differences to phylogenetically close and small-scale differences. This description of the embryology, development, and adult morphology of S. karankawa permits investigations into how acorn worm development evolves at fine scales.
PubMed: 37076909
DOI: 10.1186/s13227-023-00212-0