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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 -
Bulletin of Emergency and Trauma Jan 2021To compare the stability of the radius stabilized fractured parts by volar and dorsal planting based on modeling approach.
OBJECTIVE
To compare the stability of the radius stabilized fractured parts by volar and dorsal planting based on modeling approach.
METHODS
Ten forearm models were created based on Computed Tomography (CT) Scan images by using of Mimics software. The distal part fracture of radius was induced in the models. The stress were developed and implanted in various parts of the bone and and their displacement were evaluated in volar and dorsal inserted implants.
RESULTS
The results of this study showed that the stress developed in screws, implant and bony parts differed significantly between volar and dorsal plate conditions. The displacement of implant and bony parts in volar plating was more than dorsal plating (=0.05). However, the screws displacement in dorsal plating significantly increased compared to volar plating.
CONCLUSION
The stress developed in dorsal and volar implants is not too high to fail the structure. However, it seems that the irritation of soft tissue and tendon would be less in volar inserted implant than dorsal implant. It is recommended to use valor plating to be a good approach for stabilizing the distal part fracture of radius.
PubMed: 33937420
DOI: 10.30476/BEAT.2020.86681 -
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 -
Journal of Wrist Surgery Oct 2023The dorsal intercarpal ligament (DIC) is an elegant dorsal stabilizer of the proximal carpal row, including the scaphoid's proximal pole and scapholunate joint....
The dorsal intercarpal ligament (DIC) is an elegant dorsal stabilizer of the proximal carpal row, including the scaphoid's proximal pole and scapholunate joint. Along with the dorsal radiocarpal (DRC) ligament, it acts as a dorsal radioscaphoid stabilizer, with dynamism due to its ability to modify its length up to threefold by changing the angles between its V-shaped bundle morphology. The DIC ligament consistently originates from the dorsal tubercle of the triquetrum on the ulnar side. It spans transversely, attaching to the dorsal groove of the scaphoid (97-100%), lunate (75-90%), and proximal rim of the trapezium (12.5-50%), and overlapping the lunotriquetral interosseous ligament and the scapholunate interosseous ligament. Together with the DRC, Viegas et al (Viegas SF, Yamaguchi S, Boyd NL, Patterson RM. The dorsal ligaments of the wrist: anatomy, mechanical properties, and function. J Hand Surg Am 1999;24(3):456-468) proposed that this ligament complex should be called the "lateral-V construct." The authors present a unique type C variant of the DIC ligament, showing a distinct thick bundle directed at the dorsal aspect of the second metacarpal base that thus creates a "lateral-W construct." This dorsal triquetro-metacarpal 2 (dTqMC2) ligament acts as restraint to the body of the capitate and will provide enhanced stability of the dorsal midcarpal joint by limiting dorsal translation of the capitate in relation to the lunate. Our finding may contribute to the increasing knowledge of the dorsal ligament complex and its role in dorsal midcarpal instability, as well as surgical repair techniques.
PubMed: 37841349
DOI: 10.1055/s-0042-1758706 -
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 -
Investigative Ophthalmology & Visual... Aug 2022Retinal pigment epithelium (RPE) degeneration is a leading cause of blindness in retinal degenerative diseases, but the mechanism of RPE regional degeneration remains...
PURPOSE
Retinal pigment epithelium (RPE) degeneration is a leading cause of blindness in retinal degenerative diseases, but the mechanism of RPE regional degeneration remains largely unknown. This study aims to investigate the sensitivity of RPE to sodium iodate (SI) injury in the dorsal and ventral visual fields in mice and analyze whether overlaying cone photoreceptors regulate the sensitivity of RPE to SI-induced damage.
METHODS
SI was used to induce RPE degeneration in mice. Hematoxylin-eosin staining, immunostaining, and TUNEL assay were used to evaluate retinal degeneration along the dorsal-ventral axis. Flat-mounted and sectional retinal immunostaining were used to analyze the distribution of cones along the dorsoventral axis in C57BL/6, albino, and 129 mice. Electroretinography was used to examine the retinal function.
RESULTS
Dorsal-central RPE was more sensitive to SI-mediated injury along the dorsal-ventral axis in C57BL/6 mice. Compared with the ventral RPE, the dorsal-central RPE was dominantly covered by M cone photoreceptors in these mice. Interestingly, M cone photoreceptor degeneration was followed by dorsal RPE degeneration under a low dose of SI. Furthermore, the sensitivity of dorsal RPE to a low dose of SI was reduced in both albino and 129 mouse strains with dominant mixed cones instead of M cones in the dorsal visual field.
CONCLUSIONS
These findings suggest that dorsal-central RPE is more sensitive to SI injury and that SI-induced RPE degeneration could be controlled by modifying the dominant overlying cone population in the mouse dorsal retina, thereby highlighting a potential role of M cones in RPE regional degeneration.
Topics: Animals; Disease Models, Animal; Iodates; Mice; Mice, Inbred C57BL; Retina; Retinal Cone Photoreceptor Cells; Retinal Degeneration; Retinal Pigment Epithelium
PubMed: 36018572
DOI: 10.1167/iovs.63.9.29 -
Journal of Ultrasound Sep 2022The dorsal component of the scapholunate ligament, is the strongest component, in fact it has a maximum tensile strength of 300 N and mainly controls flexion and...
PURPOSE
The dorsal component of the scapholunate ligament, is the strongest component, in fact it has a maximum tensile strength of 300 N and mainly controls flexion and extension. In a recent study, the thickness and length of the dorsal component of SLIL was measured using ultrasound image, the length of the dorsal scapholunate ligament was 7.5 mm ± 1.4 mm and the thickness of 1.8 mm ± 0.4 mm. We evaluate 60 wrists of 30 young athletic volunteers with ultra-sound image, comparing the thickness variations of the dorsal component of SLIL between the dominant and non-dominant wrist, to confirm our hypothesis that the dorsal component SLIL has proprioceptive activity and therefore the thickness of the ligament increases in following wrist activity.
METHODS
With a high-frequency ultrasound probe > 15 MHz (Sonoscape X3 Pro) we evaluated 60 wrists of 30 young men (16 males and 14 females, 20-38 years old) manual sports volunteers (10 tennis players, 8 padel players, 7 swimmers, 5 weight lifters) with no recent ligament injuries of the hand or wrist to participate in the study, we compared the dorsal component of SLIL between the dominant and non-dominant wrist.
RESULTS
Dorsal SLIL was visualized in all 60 volunteers wrists. We measured an average scapholunate dorsal ligament length 7.7 mm and average thickness of 2.3 mm in the dominant wrist and average 7.2 mm in length and average 1.9 mm thickness in the non dominant wrist. The mean dorsal scapholunate interval was average 4.9 mm and the mean central interval was average 2.1 mm in the dominant wrist and 4.7 mm and 1.8 mm in the non dominant wrist, so that meas-urements remained unchanged with those reported by previous authors.
CONCLUSIONS
In our study we ultrasonographically measured an average scapholunate dorsal ligament length 7.7 mm and average thickness of 2.3 mm in the dominant wrist and average 7.2 mm in length and average 1.9 mm thickness in the non dominant wrist. This confirms our hypothesis that there is a direct stimulus on the ligamentous component of the dor-sal SLIL in the dominant wrist following repeated uses and activities such as to cause an increase in thickness of the dorsal ligament to highlight the possibility of a proprioceptivity of the ligament if subjected to continuous training.
LEVEL OF EVIDENCE
IV.
Topics: Adult; Female; Humans; Ligaments, Articular; Lunate Bone; Male; Scaphoid Bone; Sports; Wrist; Young Adult
PubMed: 35092602
DOI: 10.1007/s40477-021-00626-3 -
Journal of Orthopaedic Case Reports Aug 2022Compound dorsal ganglion of tubercular etiology involving the dorsum aspect of wrist is a rare entity. It is very rarely seen lately, due to early diagnosis and...
INTRODUCTION
Compound dorsal ganglion of tubercular etiology involving the dorsum aspect of wrist is a rare entity. It is very rarely seen lately, due to early diagnosis and effective treatment regimen and this case is probably the first to be reported involving the dorsum aspect of wrist.
CASE REPORT
This case report presents a 54-year-old male patient presented to us complaints of swelling and pain in dorsum of hand and wrist for 6 months. On examination, we found multiple swellings on Rt. dorsum of hand and dorsal aspect of wrist restriction of movements at wrist. After thorough clinical and radiological evaluation, patient has been posted for excision biopsy and confirmed as compound dorsal ganglion.
CONCLUSION
Compound dorsal ganglion is a disease with great diagnostic challenge due to its masquerade clinical presentation and confirmed by histopathological examination. Early diagnosis, complete debulking, and antitubercular therapy prevent further spread of disease and improves the patient functionally.
PubMed: 36687478
DOI: 10.13107/jocr.2022.v12.i08.2986 -
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