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Spine Surgery and Related Research 2020Zygapophyseal, or facet, joints are complicated biomechanical structures in the spine, with a complex three-dimensional (3D) anatomy, variable mechanical functions in... (Review)
Review
Zygapophyseal, or facet, joints are complicated biomechanical structures in the spine, with a complex three-dimensional (3D) anatomy, variable mechanical functions in different spinal movements, and effects on the overall spine mechanical behavior. The 3D morphology of the facet joint is linked to its biomechanical function. Failure of the biomechanical function of the facet joint leads to osteoarthritic changes in it and is implicated in other spinal disorders such as degenerative spondylolisthesis. Facet joints and intervertebral disk are part of an entity called the spinal motion segment, the three-joint complex, or the articular triad. Functioning together, the structures in the spinal motion segments provide physiological spinal motion, while protecting the spine by preventing activities that can be injurious. Loss of intervertebral disk height associated with disk degeneration affects the mechanical behavior of facet joints. Axial compressive load transmission through the tip of the inferior articular process can occur in the extended position, especially with reduced disk height, which may cause capsular impingement and low back pain. The 3D curvature of the articular surfaces and capsular ligaments play important roles in different spinal positions. In this review article, we will summarize the anatomy of the lumbar facet joint relevant to its biomechanical function and biomechanical behavior under different loading conditions.
PubMed: 32039290
DOI: 10.22603/ssrr.2019-0017 -
Biomolecules Sep 2020Fibulin-3 (also known as EGF-containing fibulin extracellular matrix protein 1 (EFEMP1)) is a secreted extracellular matrix glycoprotein, encoded by the gene that... (Review)
Review
Fibulin-3 (also known as EGF-containing fibulin extracellular matrix protein 1 (EFEMP1)) is a secreted extracellular matrix glycoprotein, encoded by the gene that belongs to the eight-membered fibulin protein family. It has emerged as a functionally unique member of this family, with a diverse array of pathophysiological associations predominantly centered on its role as a modulator of extracellular matrix (ECM) biology. Fibulin-3 is widely expressed in the human body, especially in elastic-fibre-rich tissues and ocular structures, and interacts with enzymatic ECM regulators, including tissue inhibitor of metalloproteinase-3 (TIMP-3). A point mutation in causes an inherited early-onset form of macular degeneration called Malattia Leventinese/Doyne honeycomb retinal dystrophy (ML/DHRD). genetic variants have also been associated in genome-wide association studies with numerous complex inherited phenotypes, both physiological (namely, developmental anthropometric traits) and pathological (many of which involve abnormalities of connective tissue function). Furthermore, expression changes are implicated in the progression of numerous types of cancer, an area in which fibulin-3 has putative significance as a therapeutic target. Here we discuss the potential mechanistic roles of fibulin-3 in these pathologies and highlight how it may contribute to the development, structural integrity, and emergent functionality of the ECM and connective tissues across a range of anatomical locations. Its myriad of aetiological roles positions fibulin-3 as a molecule of interest across numerous research fields and may inform our future understanding and therapeutic approach to many human diseases in clinical settings.
Topics: Animals; Disease Models, Animal; Extracellular Matrix; Extracellular Matrix Proteins; Genome-Wide Association Study; Humans; Optic Disk Drusen
PubMed: 32911658
DOI: 10.3390/biom10091294 -
Indian Journal of Ophthalmology Dec 2019Melanocytoma is a deeply pigmented variant of melanocytic nevus that classically occurs in the optic disk, sometimes with contiguous involvement of the adjacent retina... (Review)
Review
Melanocytoma is a deeply pigmented variant of melanocytic nevus that classically occurs in the optic disk, sometimes with contiguous involvement of the adjacent retina or choroid. Historically, this tumor was often confused with malignant melanoma both clinically and histopathologically. Today, however, it is generally recognized by its typical clinical features that differ from most melanomas and erroneous enucleation is rarely done. Histopathologically, melanocytoma is composed of intensely pigmented round to oval nevus cells with benign features. Although traditionally believed to be a relatively stationary lesion, it is now known to exhibit minor enlargement in 10--15% of cases and can cause minor visual loss by a variety of mechanisms. In rare instance, it can induce severe visual loss due to spontaneous necrosis of the lesion or compressive optic neuropathy. More importantly, it can exhibit malignant transformation into melanoma in 1--2% of cases. Ophthalmologists should be familiar with melanocytoma of the optic disk and affected patients should be followed periodically.
Topics: Cell Transformation, Neoplastic; Humans; Melanoma; Nevus, Pigmented; Optic Disk; Optic Nerve Neoplasms
PubMed: 31755427
DOI: 10.4103/ijo.IJO_2039_19 -
Frontiers in Bioengineering and... 2021Low-back and neck-shoulder pains caused by intervertebral disk degeneration are highly prevalent among middle-aged and elderly people globally. The main therapy method... (Review)
Review
Low-back and neck-shoulder pains caused by intervertebral disk degeneration are highly prevalent among middle-aged and elderly people globally. The main therapy method for intervertebral disk degeneration is surgical intervention, including interbody fusion, disk replacement, and diskectomy. However, the stress changes caused by traditional fusion surgery are prone to degeneration of adjacent segments, while non-fusion surgery has problems, such as ossification of artificial intervertebral disks. To overcome these drawbacks, biomaterials that could endogenously regenerate the intervertebral disk and restore the biomechanical function of the intervertebral disk is imperative. Intervertebral disk is a fibrocartilaginous tissue, primarily comprising nucleus pulposus and annulus fibrosus. Nucleus pulposus (NP) contains high water and proteoglycan, and its main function is absorbing compressive forces and dispersing loads from physical activities to other body parts. Annulus fibrosus (AF) is a multilamellar structure that encloses the NP, comprises water and collagen, and supports compressive and shear stress during complex motion. Therefore, different biomaterials and tissue engineering strategies are required for the functional recovery of NP and AF based on their structures and function. Recently, great progress has been achieved on biomaterials for NP and AF made of functional polymers, such as chitosan, collagen, polylactic acid, and polycaprolactone. However, scaffolds regenerating intervertebral disk remain unexplored. Hence, several tissue engineering strategies based on cell transplantation and growth factors have been extensively researched. In this review, we summarized the functional polymers and tissue engineering strategies of NP and AF to endogenously regenerate degenerative intervertebral disk. The perspective and challenges of tissue engineering strategies using functional polymers, cell transplantation, and growth factor for generating degenerative intervertebral disks were also discussed.
PubMed: 34746112
DOI: 10.3389/fbioe.2021.766087 -
PloS One 2022While zebrafish represent an important model for the study of the visual system, visual perception in this species is still less investigated than in other teleost fish....
While zebrafish represent an important model for the study of the visual system, visual perception in this species is still less investigated than in other teleost fish. In this work, we validated for zebrafish two versions of a visual discrimination learning task, which is based on the motivation to reach food and companions. Using this task, we investigated zebrafish ability to discriminate between two different shape pairs (i.e., disk vs. cross and full vs. amputated disk). Once zebrafish were successfully trained to discriminate a full from an amputated disk, we also tested their ability to visually complete partially occluded objects (amodal completion). After training, animals were presented with two amputated disks. In these test stimuli, another shape was either exactly juxtaposed or only placed close to the missing sectors of the disk. Only the former stimulus should elicit amodal completion. In human observers, this stimulus causes the impression that the other shape is occluding the missing sector of the disk, which is thus perceived as a complete, although partially hidden, disk. In line with our predictions, fish reinforced on the full disk chose the stimulus eliciting amodal completion, while fish reinforced on the amputated disk chose the other stimulus. This represents the first demonstration of amodal completion perception in zebrafish. Moreover, our results also indicated that a specific shape pair (disk vs. cross) might be particularly difficult to discriminate for this species, confirming previous reports obtained with different procedures.
Topics: Animals; Discrimination Learning; Discrimination, Psychological; Form Perception; Pattern Recognition, Visual; Visual Perception; Zebrafish
PubMed: 35235595
DOI: 10.1371/journal.pone.0264127 -
Spine Surgery and Related Research 2022Intervertebral disk degeneration is a universal and natural process. However, no reports have summarized anatomical age-related intervertebral disk height and disk...
INTRODUCTION
Intervertebral disk degeneration is a universal and natural process. However, no reports have summarized anatomical age-related intervertebral disk height and disk degenerative changes in the thoracolumbar spine or examined sex-specific differences. This study aimed to establish age-related changes and gender-specific differences of intervertebral disk height and disk degeneration of the thoracolumbar spine in a large cohort of relatively healthy subjects and also to evaluate the relationship between the degree of thoracolumbar disk height and disk degeneration.
METHODS
Six hundred and twenty-seven relatively healthy subjects (307 males and 320 females; average age, 49.6±16.5 years) were enrolled. We included at least 50 males and 50 females in each decade of life between the 20s and the 70s. We measured intervertebral disk height from T10/T11 to L5/S1, vertebral body height from T10 to S1 on lateral neutral radiographs. Lumbar disk degeneration was defined according to the Pfirrmann classification in sagittal plane magnetic resonance imaging.
RESULTS
Age-related decreases in intervertebral disk height were most prominent at L4/L5 in middle-aged and elderly individuals of both sexes. The grade of disk degeneration significantly increased with age in both genders at every level. Mild disk degeneration was observed even in the 20s. The disk degeneration occurred around the L4/L5 level. Although grade V disk degeneration was not identified for males in the 20s and the 30s, it appeared after the 40s and then increased further with age. The intervertebral disk height at the lower lumbar disks decreased with a progression in the disk degeneration grade in both genders.
CONCLUSIONS
This large-scale cross-sectional analysis of the thoracolumbar spine in relatively healthy subjects demonstrated that lumbar disk height narrowing progresses with age and is correlated with the progression of disk degeneration.
PubMed: 36051683
DOI: 10.22603/ssrr.2021-0187 -
Veterinary Surgery : VS May 2021To describe the clinical presentation, magnetic resonance imaging (MRI) findings, and outcome of dogs treated surgically for lumbosacral intervertebral disk extrusion...
OBJECTIVE
To describe the clinical presentation, magnetic resonance imaging (MRI) findings, and outcome of dogs treated surgically for lumbosacral intervertebral disk extrusion (IVDE).
STUDY DESIGN
Retrospective study.
ANIMALS
Thirteen dogs.
METHODS
Records and MRI studies of dogs with intraoperatively confirmed lumbosacral IVDE were reviewed. MRI features of thoracolumbar IVDE were applied to all cases. Postoperative outcome was subjectively assessed as excellent, good, or poor.
RESULTS
All dogs had an acute or subacute onset of lumbosacral pain and nerve root signature. Seven dogs had neurological deficits. MRI revealed lateralized herniated disk material and partial to complete disk degeneration in all cases; the extradural material extended cranial and/or caudally from the disk space in 10 cases. All dogs underwent L7-S1 dorsal laminectomy and removal of extruded disk material. In six dogs, surgery was complicated by inflammatory changes, including one case of epidural steatitis. On reexamination 4-6 weeks postsurgery, outcome was judged as excellent in 11 dogs and poor in the remaining 2 due to contralateral nerve root signature in one case and nonambulatory paraparesis and urinary incontinence in the case with steatitis.
CONCLUSION
Lumbosacral IVDE in dogs was characterized by acute/subacute onset of lumbosacral pain and nerve root signature and lateralized and often dispersed extradural material over a degenerated L7-S1 intervertebral disk on MRI. Early decompressive dorsal laminectomy generally resulted in excellent clinical outcome.
CLINICAL SIGNIFICANCE
Observation of these clinical and imaging features in dogs should prompt clinical suspicion of lumbosacral IVDE.
Topics: Animals; Dog Diseases; Dogs; Female; Intervertebral Disc Degeneration; Intervertebral Disc Displacement; Laminectomy; Lumbosacral Region; Male; Preoperative Period; Retrospective Studies; Treatment Outcome
PubMed: 33749866
DOI: 10.1111/vsu.13624 -
Indian Journal of Ophthalmology Aug 2023Prepapillary vascular loops are a type of congenital vascular anomaly seen on or around the optic disk. Patients with this condition are usually asymptomatic and are...
BACKGROUND
Prepapillary vascular loops are a type of congenital vascular anomaly seen on or around the optic disk. Patients with this condition are usually asymptomatic and are detected incidentally on routine fundus examinations. Differential diagnosis for this condition includes neovascularization of the disk and collaterals on the disk. Prepapillary capillary loops are not associated with any systemic condition. They are usually unilateral in presentation, but can rarely be bilateral.
PURPOSE
To discuss the new proposed classification of prepapillary capillary loops.
SYNOPSIS
: Prepapillary capillary loops are classified based on their location around the disk, loop characteristics such as elevation, shape, and covering, and presence of vitreoretinal traction.
HIGHLIGHTS
The most common vascular loops are arterial in origin and rarely venous in origin. They can sometimes be associated with spontaneous and recurrent vitreous hemorrhage, branch retinal artery or vein occlusion, and subretinal hemorrhage. It is an important differential diagnosis in spontaneous vitreous hemorrhage. Treatment is symptomatic.
VIDEO LINK
: https://youtu.be/gbq_oP7Y2q4.
Topics: Humans; Vitreous Hemorrhage; Retinal Vessels; Retinal Artery; Eye Abnormalities
PubMed: 37530298
DOI: 10.4103/IJO.IJO_639_23 -
Journal of Clinical Microbiology Jul 2023Sulopenem disk masses of 2, 5, 10, and 20 μg were evaluated by susceptibility testing isolates by broth microdilution and disk diffusion. A 2-μg disk was chosen, and...
Sulopenem disk masses of 2, 5, 10, and 20 μg were evaluated by susceptibility testing isolates by broth microdilution and disk diffusion. A 2-μg disk was chosen, and error-rate bounding analysis in accordance with Clinical and Laboratory Standards Institute (CLSI) guideline M23 was conducted using a proposed sulopenem susceptible/intermediate/resistant (S/I/R) interpretive criterion of ≤0.5/1/≥2 μg/mL. Among the evaluated ( = 2,856), very few interpretive errors were observed (no very major errors and only one major error). An eight-laboratory quality control (QC) study was performed using the 2-μg disk, and 99.0% (470/475) of results were within a 7-mm range of 24 to 30 mm. Results were similar by disk lot and media, and no outlier sites were observed. A sulopenem 2-μg disk QC range for Escherichia coli 29522 of 24 to 30 mm was established by the CLSI. A 2-μg sulopenem disk performs accurately and reproducibly for testing of .
Topics: Humans; Anti-Bacterial Agents; Microbial Sensitivity Tests; Lactams; Quality Control; Escherichia coli
PubMed: 37358462
DOI: 10.1128/jcm.00246-23 -
Frontiers in Microbiology 2023As society ages, the number of patients with spinal degenerative diseases (SDD) is increasing, posing a major socioeconomic problem for patients and their families. SDD... (Review)
Review
As society ages, the number of patients with spinal degenerative diseases (SDD) is increasing, posing a major socioeconomic problem for patients and their families. SDD refers to a generic term for degenerative diseases of spinal structures, including osteoporosis (bone), facet osteoarthritis (joint), intervertebral disk degeneration (disk), lumbar spinal canal stenosis (yellow ligament), and spinal sarcopenia (muscle). We propose the term "gut-spine axis" for the first time, given the influence of gut microbiota (GM) on the metabolic, immune, and endocrine environment in hosts through various potential mechanisms. A close cross-talk is noted between the aforementioned spinal components and degenerative diseases. This review outlines the nature and role of GM, highlighting GM abnormalities associated with the degeneration of spinal components. It also summarizes the evidence linking GM to various SDD. The gut-spine axis perspective can provide novel insights into the pathogenesis and treatment of SDD.
PubMed: 37965563
DOI: 10.3389/fmicb.2023.1290858