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Cells Jan 2022The ventricular-subventricular zone (V-SVZ) is a postnatal germinal niche. It holds a large population of neural stem cells (NSCs) that generate neurons and...
The ventricular-subventricular zone (V-SVZ) is a postnatal germinal niche. It holds a large population of neural stem cells (NSCs) that generate neurons and oligodendrocytes for the olfactory bulb and (primarily) the corpus callosum, respectively. These NSCs are heterogeneous and generate different types of neurons depending on their location. Positional identity among NSCs is thought to be controlled in part by intrinsic pathways. However, extrinsic cell signaling through the secreted ligand Sonic hedgehog (Shh) is essential for neurogenesis in both the dorsal and ventral V-SVZ. Here we used a genetic approach to investigate the role of the transcription factors GLI2 and GLI3 in the proliferation and cell fate of dorsal and ventral V-SVZ NSCs. We find that while GLI3 is expressed in stem cell cultures from both dorsal and ventral V-SVZ, the repressor form of GLI3 is more abundant in dorsal V-SVZ. Despite this high dorsal expression and the requirement for other Shh pathway members, GLI3 loss affects the generation of ventrally-, but not dorsally-derived olfactory interneurons in vivo and does not affect trilineage differentiation in vitro. However, loss of GLI3 in the adult dorsal V-SVZ in vivo results in decreased numbers of OLIG2-expressing progeny, indicating a role in gliogenesis.
Topics: Adult Stem Cells; Animals; Cell Differentiation; Cells, Cultured; Interneurons; Lateral Ventricles; Mice; Nerve Tissue Proteins; Neural Stem Cells; Oligodendrocyte Transcription Factor 2; Smoothened Receptor; Zinc Finger Protein Gli3
PubMed: 35053334
DOI: 10.3390/cells11020218 -
Annals of Intensive Care Feb 2022A sequential change in body position from supine-to-both lateral positions under constant ventilatory settings could be used as a postural recruitment maneuver in case...
BACKGROUND
A sequential change in body position from supine-to-both lateral positions under constant ventilatory settings could be used as a postural recruitment maneuver in case of acute respiratory distress syndrome (ARDS), provided that sufficient positive end-expiratory pressure (PEEP) prevents derecruitment. This study aims to evaluate the feasibility and physiological effects of a sequential postural recruitment maneuver in early mechanically ventilated COVID-19 ARDS patients.
METHODS
A cohort of 15 patients receiving lung-protective mechanical ventilation in volume-controlled with PEEP based on recruitability were prospectively enrolled and evaluated in five sequentially applied positions for 30 min each: Supine-baseline; Lateral-1st side; 2nd Supine; Lateral-2nd side; Supine-final. PEEP level was selected using the recruitment-to-inflation ratio (R/I ratio) based on which patients received PEEP 12 cmHO for R/I ratio ≤ 0.5 or PEEP 15 cmHO for R/I ratio > 0.5. At the end of each period, we measured respiratory mechanics, arterial blood gases, lung ultrasound aeration, end-expiratory lung impedance (EELI), and regional distribution of ventilation and perfusion using electric impedance tomography (EIT).
RESULTS
Comparing supine baseline and final, respiratory compliance (29 ± 9 vs 32 ± 8 mL/cmHO; p < 0.01) and PaO/FIO ratio (138 ± 36 vs 164 ± 46 mmHg; p < 0.01) increased, while driving pressure (13 ± 2 vs 11 ± 2 cmHO; p < 0.01) and lung ultrasound consolidation score decreased [5 (4-5) vs 2 (1-4); p < 0.01]. EELI decreased ventrally (218 ± 205 mL; p < 0.01) and increased dorsally (192 ± 475 mL; p = 0.02), while regional compliance increased in both ventral (11.5 ± 0.7 vs 12.9 ± 0.8 mL/cmHO; p < 0.01) and dorsal regions (17.1 ± 1.8 vs 18.8 ± 1.8 mL/cmHO; p < 0.01). Dorsal distribution of perfusion increased (64.8 ± 7.3% vs 66.3 ± 7.2%; p = 0.01).
CONCLUSIONS
Without increasing airway pressure, a sequential postural recruitment maneuver improves global and regional respiratory mechanics and gas exchange along with a redistribution of EELI from ventral to dorsal lung areas and less consolidation. Trial registration ClinicalTrials.gov, NCT04475068. Registered 17 July 2020, https://clinicaltrials.gov/ct2/show/NCT04475068.
PubMed: 35150355
DOI: 10.1186/s13613-022-00988-9 -
Frontiers in Cell and Developmental... 2022Dorsal closure is a prominent morphogenetic process during embryogenesis, which involves two epithelial tissues, that is, the squamous amnioserosa and the columnar...
Dorsal closure is a prominent morphogenetic process during embryogenesis, which involves two epithelial tissues, that is, the squamous amnioserosa and the columnar lateral epidermis. Non-muscle myosin II-driven constriction in the amnioserosa leads to a decrease in the apical surface area and pulls on the adjacent lateral epidermis, which subsequently moves dorsally. The pull by the amnioserosa becomes obvious in an elongation of the epidermal cells, especially of those in the first row. The contribution of the epidermal cell elongation has remained unclear to dorsal closure. Cell elongation may be a mere passive consequence or an active response to the pulling by the amnioserosa. Here, we found that the lateral epidermis actively responds. We analyzed tensions within tissues and cell junctions by laser ablation before and during dorsal closure, the elliptical and dorsal closure stages, respectively. Furthermore, we genetically and optochemically induced chronic and acute cell contraction, respectively. In this way, we found that tension in the epidermis increased during dorsal closure. A correspondingly increased tension was not observed at individual junctions, however. Junctional tension even decreased during dorsal closure in the epidermis. We strikingly observed a strong increase of the microtubule amount in the epidermis, while non-muscle myosin II increased in both tissues. Our data suggest that the epidermis actively antagonizes the pull from the amnioserosa during dorsal closure and the increased microtubules might help the epidermis bear part of the mechanical force.
PubMed: 35652100
DOI: 10.3389/fcell.2022.865397 -
Frontiers in Cellular Neuroscience 2021Dorsal and median raphe nuclei (DR and MR, respectively) are members of the reticular activating system and play important role in the regulation of the...
Dorsal and median raphe nuclei (DR and MR, respectively) are members of the reticular activating system and play important role in the regulation of the sleep-wakefulness cycle, movement, and affective states. M-current is a voltage-gated potassium current under the control of neuromodulatory mechanisms setting neuronal excitability. Our goal was to determine the proportion of DR and MR serotonergic neurons possessing M-current and whether they are organized topographically. Electrophysiological parameters of raphe serotonergic neurons influenced by this current were also investigated. We performed slice electrophysiology on genetically identified serotonergic neurons. Neurons with M-current are located rostrally in the DR and dorsally in the MR. M-current determines firing rate, afterhyperpolarization amplitude, and adaptation index (AI) of these neurons, but does not affect input resistance, action potential width, and high threshold oscillations.These findings indicate that M-current has a strong impact on firing properties of certain serotonergic neuronal subpopulations and it might serve as an effective contributor to cholinergic and local serotonergic neuromodulatory actions.
PubMed: 33716672
DOI: 10.3389/fncel.2021.614947 -
Trauma Case Reports Apr 2023Bennet's fracture represents one of the most common injuries of the hand district, involving the base of the thumb, and it is affects children and elderly patients the...
Bennet's fracture represents one of the most common injuries of the hand district, involving the base of the thumb, and it is affects children and elderly patients the most. The fracture is caused by direct axial trauma to a partially flexed first metacarpal and it is always intra-articular: the fracture line separates the palmar ulnar aspect of the first metacarpal base from the remaining first metacarpal. The fracture pattern is such that the first metacarpal shaft moves dorsally, proximally, and radially due to the pull of the abductor pollicis longus, extensor pollicis longus, extensor pollicis brevis, and the adductor pollicis brevis, which remain attached to the fracture fragment. The surgical treatment consists of closed reduction with percutaneous pinning or open reduction with either pins or interfragmentary screws. The decision to treat these fractures with either open reduction or closed reduction is still a matter of debate. To the best of our knowledge, there are no cases of bilateral Bennett's fracture reported in literature. The aim of this paper is to present a rare case of bilateral Bennet's fracture, the decision of two different treatments, and the good clinical outcomes.
PubMed: 36851906
DOI: 10.1016/j.tcr.2023.100786 -
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 -
Cureus Nov 2017Accessory ossicles of the foot and ankle are normal variants of bone development that usually remain asymptomatic. However, they may be involved in various disorders... (Review)
Review
Accessory ossicles of the foot and ankle are normal variants of bone development that usually remain asymptomatic. However, they may be involved in various disorders and become a source of pain such as in fractures, dislocations, degenerative changes, osteonecrosis, osteoarthritis, osteochondral lesions, avascular necrosis, and irritation or impingement of adjacent soft tissues. Hence, during the assessment of the situations above, knowledge about these little-known ossicles could be very important to reach the correct diagnosis. Recent studies in the literature have mostly focused on the most frequent 9-12 accessory bones. In this review, 24 types of accessory ossicle are described. These ossicles are accessory navicular bone, os peroneum, os trigonum, os intermetatarseum, os vesalianum. os subfibulare, os subtibiale, os calcaneus secundarius, os calcanei accessorium, os supratalare, os sustentaculi, os talotibiale, os tali accessorium, talus secundarius, os subcalcis, os cuboideum secundarium, os supranaviculare, os infranaviculare, os paracuneiforme, os intercuneiforme, os cuneometatarsale I tibiale, os cuneometatarsale plantare, os cuneo-I metatarsale-II dorsale, and os aponeurosis plantaris. The clinical importance of these bones should be known thoroughly to reduce unnecessary orthopedic consultations and misdiagnosis. This article describes the clinical importance of the accessory ossicles and their possible pathological conditions. Understanding the possible disorders of the accessory ossicles of the foot and ankle can provide a more accurate diagnostic process.
PubMed: 29387510
DOI: 10.7759/cureus.1881 -
Cureus Aug 2021Bilateral Galeazzi fracture-dislocations are extremely rare injuries and only a few case reports have been described so far in the literature. Herein, we report the case...
Bilateral Galeazzi fracture-dislocations are extremely rare injuries and only a few case reports have been described so far in the literature. Herein, we report the case of a 31-year-old bicyclist whosustained bilateral Galeazzi fracture-dislocations after a collision with a car. Both radial shaft fractures were simple (AO type 22-A2.3), at the same level (Type I: <7.5 cm from the joint line), and without severe comminution having their apex located dorsally. Internal fixation was accomplished in both fractures with an 8-hole, 3.5-mm locking plate; the stability of the distal radioulnar joint (DRUJ) was assessed with several intraoperative tests and found to be stable so that no additional stabilization was necessary. Postoperatively, the forearms were immobilized in a long forearm cast for four weeks. At the last follow-up evaluation, six years postoperatively, the patient was pain-free, had a full range of motion with a total Mayo wrist score of 95 in both wrists. Bilateral Galeazzi fracture-dislocations are rare injuries requiring proper radial fracture management and thorough assessment of DRUJ stability.
PubMed: 34603873
DOI: 10.7759/cureus.17491 -
PloS One 2021The purpose of this study was to biomechanically compare the stability of first metatarsophalangeal (MTP1) joint arthrodesis with dorsally and medially positioned plates.
OBJECTIVE
The purpose of this study was to biomechanically compare the stability of first metatarsophalangeal (MTP1) joint arthrodesis with dorsally and medially positioned plates.
METHODS
A physical model of the MTP1 joint consists of printed synthetic bones, a titanium locking plate and screws. In the experiments, samples with dorsally and medially positioned plates were subjected to loading of ground load character in a universal testing machine. Force-displacement relations and relative displacements of bones were recorded. The obtained results were used to validate the corresponding finite element models of the MTP1 joint. Nonlinear finite element simulations of the toe-off phase of gait were performed to determine the deformation and stress state in the MTP1 joint for two positions of the plate.
RESULTS
In numerical simulations, the maximum displacement in the dorsal direction was noticed at the tip of the distal phalanx and was equal to 19.6 mm for the dorsal plate and 9.63 mm for the medial plate for a resultant force of 150 N. Lower relative bone displacements and smaller plastic deformation in the plate were observed in the model with the medial plate. Stress values were also smaller in the medially positioned plate and locking screws compared to fixation with the dorsal plate.
CONCLUSIONS
A medially positioned locking plate provides better stability of the MTP1 joint than a dorsally positioned plate due to greater vertical bending stiffness of the medial plate. Smaller relative bone displacements observed in fixation with the medial plate may be beneficial for the bone healing process. Moreover, lower stress values may decrease the risk of complications associated with hardware failure.
Topics: Arthrodesis; Biomechanical Phenomena; Bone Plates; Bone and Bones; Finite Element Analysis; Humans; Metatarsophalangeal Joint; Models, Anatomic; Stress, Mechanical
PubMed: 34852005
DOI: 10.1371/journal.pone.0260572 -
International Journal of Molecular... Dec 2022and are recognized as members of the genus because of their dorsally compressed mericarps with slightly prominent dorsal ribs and narrowly winged lateral ribs....
and are recognized as members of the genus because of their dorsally compressed mericarps with slightly prominent dorsal ribs and narrowly winged lateral ribs. However, these species are not similar to other taxa but resemble in overall morphology. To check the taxonomic positions of and , we sequenced their complete plastid genome (plastome) sequences and, together with eleven previously published plastomes, performed comprehensively comparative analyses. The thirteen plastomes were highly conserved and similar in structure, size, GC content, gene content and order, IR borders, and the patterns of codon bias, RNA editing, and simple sequence repeats (SSRs). Nevertheless, twelve mutation hotspots (K, C, 15, 8, 2, A-D, N-M, A-K, 2-C2, 4-T, H-A, and 2-L) were selected. Moreover, both the phylogenetic analyses based on plastomes and on nuclear ribosomal DNA internal transcribed spacer (ITS) sequences robustly supported that and nested in , and this was further confirmed by the morphological evidence. Hence, transferring and into genus is reasonable and convincing, and two new combinations are presented.
Topics: Apiaceae; Magnoliopsida; Phylogeny; Genome, Plastid; Plastids
PubMed: 36613825
DOI: 10.3390/ijms24010382