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Frontiers in Neurology 2023Over the years, most back pain-related biological studies focused on the pathogenesis of disk degeneration. It is known that nerve distributions at the outer layer of...
INTRODUCTION
Over the years, most back pain-related biological studies focused on the pathogenesis of disk degeneration. It is known that nerve distributions at the outer layer of the annulus fibrosus (AF) may be an important contributor to back pain symptoms. However, the types and origins of sensory nerve terminals in the mouse lumbar disks have not been widely studied. Using disk microinjection and nerve retrograde tracing methods, the current study aimed to characterize the nerve types and neuropathway of the lumbar 5/6 (L5/6) disk in mice.
METHODS
Using an anterior peritoneal approach, the L5/6 disk of adult C57BL/6 mice (males, 8-12 weeks) disk microinjection was performed. Fluorogold (FG) was injected into the L5/6 disk using the Hamilton syringe with a homemade glass needle driven by a pressure microinjector. The lumbar spine and bilateral thoracic 13 (Th13) to L6 DRGs were harvested at 10 days after injection. The number of FG neurons among different levels was counted and analyzed. Different nerve markers, including anti-neurofilament 160/200 (NF160/200), anti-calcitonin gene-related peptide (CGRP), anti-parvalbumin (PV), and anti-tyrosine hydroxylase (TH), were used to identify different types of nerve terminals in AF and their origins in DRG neurons.
RESULTS
There were at least three types of nerve terminals at the outer layer of L5/6 AF in mice, including NF160/200 (indicating Aβ fibers), CGRP (Aδ and C fibers), and PV (proprioceptive fibers). No TH fibers (sympathetic nerve fibers and some C-low threshold mechanoreceptors) were noticed in either. Using retrograde tracing methods, we found that nerve terminals in the L5/6 disk were multi-segmentally from Th13-L6 DRGs, with L1 and L5 predominately. An immunofluorescence analysis revealed that FG neurons in DRGs were co-localized with NF160/200, CGRP, and PV, but not TH.
CONCLUSION
Intervertebral disks were innervated by multiple types of nerve fibers in mice, including Aβ, Aδ, C, and proprioceptive fibers. No sympathetic nerve fibers were found in AF. The nerve network of the L5/6 disk in mice was multi-segmentally innervated by the Th13-L6 DRGs (mainly L1 and L5 DRGs). Our results may serve as a reference for preclinical studies of discogenic pain in mice.
PubMed: 37077575
DOI: 10.3389/fneur.2023.1084209 -
Journal of the American Veterinary... Oct 2008To quantify the association between intervertebral disk calcification and disk herniation in Dachshunds.
OBJECTIVE
To quantify the association between intervertebral disk calcification and disk herniation in Dachshunds.
DESIGN
Longitudinal study.
ANIMALS
61 Dachshunds that had been radiographically screened for calcification of intervertebral disks at 2 years of age in other studies. Thirty-seven of the dogs had survived to the time of the present study and were > or = 8 years of age; 24 others had not survived.
PROCEDURES
Radiographic examination of 36 surviving dogs was performed, and information on occurrence of disk calcification at 2 years of age were obtained from records of all 61 Dachshunds. Information on occurrence of disk herniation between 2 and 8 years of age was obtained from owners via questionnaire. Associations between numbers of calcified disks and disk herniation were analyzed via maximum likelihood logistic regression.
RESULTS
Disk calcification at 2 years of age was a significant predictor of clinical disk herniation (odds ratio per calcified disk, 1.42; 95% confidence interval, 1.19 to 1.81). Number of calcified disks in the full vertebral column was a better predictor than number of calcified disks between vertebrae T10 and L3. Numbers of calcified disks at > or = 8 years of age and at 2 years of age were significantly correlated.
CONCLUSIONS AND CLINICAL RELEVANCE
Number of calcified disks at 2 years of age was a good predictor of clinical disk herniation in Dachshunds. Because of the high heritability of disk calcification, it is possible that an effective reduction in occurrence of severe disk herniation in Dachshunds could be obtained by selective breeding against high numbers of calcified disks at 2 years of age.
Topics: Age Factors; Animals; Breeding; Calcinosis; Dog Diseases; Dogs; Female; Genetic Predisposition to Disease; Incidence; Intervertebral Disc; Logistic Models; Longitudinal Studies; Male; Predictive Value of Tests; Radiography; Severity of Illness Index; Spinal Diseases
PubMed: 18828719
DOI: 10.2460/javma.233.7.1090 -
Frontiers in Bioengineering and... 2015Capturing patient- or condition-specific intervertebral disk (IVD) properties in finite element models is outmost important in order to explore how biomechanical and... (Review)
Review
Capturing patient- or condition-specific intervertebral disk (IVD) properties in finite element models is outmost important in order to explore how biomechanical and biophysical processes may interact in spine diseases. However, disk degenerative changes are often modeled through equations similar to those employed for healthy organs, which might not be valid. As for the simulated effects of degenerative changes, they likely depend on specific disk geometries. Accordingly, we explored the ability of continuum tissue models to simulate disk degenerative changes. We further used the results in order to assess the interplay between these simulated changes and particular IVD morphologies, in relation to disk cell nutrition, a potentially important factor in disk tissue regulation. A protocol to derive patient-specific computational models from clinical images was applied to different spine specimens. In vitro, IVD creep tests were used to optimize poro-hyperelastic input material parameters in these models, in function of the IVD degeneration grade. The use of condition-specific tissue model parameters in the specimen-specific geometrical models was validated against independent kinematic measurements in vitro. Then, models were coupled to a transport-cell viability model in order to assess the respective effects of tissue degeneration and disk geometry on cell viability. While classic disk poro-mechanical models failed in representing known degenerative changes, additional simulation of tissue damage allowed model validation and gave degeneration-dependent material properties related to osmotic pressure and water loss, and to increased fibrosis. Surprisingly, nutrition-induced cell death was independent of the grade-dependent material properties, but was favored by increased diffusion distances in large IVDs. Our results suggest that in situ geometrical screening of IVD morphology might help to anticipate particular mechanisms of disk degeneration.
PubMed: 25717471
DOI: 10.3389/fbioe.2015.00005 -
Microbiology Spectrum Feb 2022The objective of this research was to evaluate the correlation between inhibitory zones and MIC when testing ceftazidime-avibactam using disk diffusion, Etest, and broth... (Comparative Study)
Comparative Study
The objective of this research was to evaluate the correlation between inhibitory zones and MIC when testing ceftazidime-avibactam using disk diffusion, Etest, and broth microdilution method established by the Clinical and Laboratory Standards Institute (CLSI). Four-hundred and 58 isolates of isolated from 54 medical centers from the China Antimicrobial Surveillance Network (CHINET) in 2016 to 2020 were collected. Antimicrobial susceptibility testing using broth microdilution, Etest, and disk diffusion were performed according to the CLSI. Of the 458 , 17.2% (79/458) and 82.8%(379/458) were resistant or susceptible to ceftazidime-avibactam by broth microdilution, respectively. Compared with the broth microdilution method, the categorical agreement (CA) and essential agreement (EA) of the Etest were 99.6% (456/458) and 94.8% (434/458), respectively; the major error (ME) and very major error (VME) were both 0.2% (1/458). For disk diffusion, the CA and VME were 99.8% (457/458) and 0.2% (1/458), respectively. For Escherichia coli, the CA and EA of the Etest were 100% and 97.1% (135/139), respectively. The CA of the disk diffusion was 100%. For Klebsiella pneumoniae, the CA and EA of the Etest were 99.3% (288/290) and 93.4% (271/290), respectively, the ME and VME were both 0.3% (1/290). The CA and VME of disk diffusion were 99.7% (289/290) and 0.3% (1/290), respectively. For other , the CA and EA of the Etest were 100% and 96.6% (28/29), respectively. The CA of the disk diffusion was 100%. Ceftazidime-avibactam disk diffusion (30/20-μg disks) and Etest demonstrated good performance for ceftazidime-avibactam susceptibility testing against clinical isolates. Multidrug-resistant Gram-negative bacteria, especially for extended-spectrum β-lactamases-producing and carbapenemase-producing , are disseminating rapidly around the world. Treatment options for these infections are limited, which prompt the development of novel or combinational therapies to combat the infections caused by multidrug-resistant pathogens. The newly available β-lactam combination agent ceftazidime-avibactam has been demonstrated good and activity against ESBL, AmpC, KPC-2, or OXA-48-like-producing isolates and has shown promise in treating carbapenem-resistant infections. Concerningly, there are few available automated systems for ceftazidime-avibactam susceptibility testing, and the broth microdilution method is hard to perform in most routine laboratories. Therefore, we urgently need an economical and practical method for the accurate detection of ceftazidime-avibactam activity against Gram-negative bacilli. Here, we evaluate the performance of the disk diffusion and Etest compared with the reference broth microdilution method against clinical strains.
Topics: Anti-Bacterial Agents; Azabicyclo Compounds; Ceftazidime; Disk Diffusion Antimicrobial Tests; Drug Combinations; Drug Resistance, Multiple, Bacterial; Enterobacteriaceae; Enterobacteriaceae Infections; Humans
PubMed: 35019685
DOI: 10.1128/spectrum.01092-21 -
Journal of Clinical Microbiology Mar 2016Staphylococcus pseudintermedius is a coagulase-positive species that colonizes the nares and anal mucosa of healthy dogs and cats. Human infections with S....
Evaluation of Oxacillin and Cefoxitin Disk and MIC Breakpoints for Prediction of Methicillin Resistance in Human and Veterinary Isolates of Staphylococcus intermedius Group.
Staphylococcus pseudintermedius is a coagulase-positive species that colonizes the nares and anal mucosa of healthy dogs and cats. Human infections with S. pseudintermedius range in severity from bite wounds and rhinosinusitis to endocarditis; historically, these infections were thought to be uncommon, but new laboratory methods suggest that their true incidence is underreported. Oxacillin and cefoxitin disk and MIC tests were evaluated for the detection of mecA- or mecC-mediated methicillin resistance in 115 human and animal isolates of the Staphylococcus intermedius group (SIG), including 111 Staphylococcus pseudintermediusand 4 Staphylococcus delphini isolates, 37 of which were mecA positive. The disk and MIC breakpoints evaluated included the Clinical and Laboratory Standards Institute (CLSI) M100-S25 Staphylococcus aureus/Staphylococcus lugdunensis oxacillin MIC breakpoints and cefoxitin disk and MIC breakpoints, the CLSI M100-S25 coagulase-negative Staphylococcus (CoNS) oxacillin MIC breakpoint and cefoxitin disk breakpoint, the CLSI VET01-S2 S. pseudintermedius oxacillin MIC and disk breakpoints, and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) S. pseudintermedius cefoxitin disk breakpoint. The oxacillin results interpreted by the VET01-S2 (disk and MIC) and M100-S25 CoNS (MIC) breakpoints agreed with the results of mecA/mecC PCR for all isolates, with the exception of one false-resistant result (1.3% of mecA/mecC PCR-negative isolates). In contrast, cefoxitin tests performed poorly, ranging from 3 to 89% false susceptibility (very major errors) and 0 to 48% false resistance (major errors). BD Phoenix, bioMérieux Vitek 2, and Beckman Coulter MicroScan commercial automated susceptibility test panel oxacillin MIC results were also evaluated and demonstrated >95% categorical agreement with mecA/mecC PCR results if interpreted by using the M100-S25 CoNS breakpoint. The Alere penicillin-binding protein 2a test accurately detected all mecA-positive isolates, although for four isolates, cefoxitin induction was required prior to testing. These data demonstrate that the cefoxitin surrogate test does not reliably detect the presence of mecA in S. pseudintermedius isolates and that laboratories should perform oxacillin disk or MIC tests of these isolates when they are encountered.
Topics: Animals; Cefoxitin; Humans; Methicillin Resistance; Microbial Sensitivity Tests; Oxacillin; Staphylococcal Infections; Staphylococcus intermedius
PubMed: 26607988
DOI: 10.1128/JCM.02864-15 -
Spine Surgery and Related Research 2021Despite being originally developed for the evaluation of lumbar disk degeneration, the Pfirrmann classification has emerged as the most popular classification system for...
INTRODUCTION
Despite being originally developed for the evaluation of lumbar disk degeneration, the Pfirrmann classification has emerged as the most popular classification system for cervical disk degeneration. However, with the Suzuki classification, a new classification system that is specifically tailored for the evaluation of cervical disk disease was introduced. In this study, we aim to evaluate differences in inter- and intraobserver reliability of both classifications in a head-to-head comparison.
METHODS
In total, we have evaluated 120 cervical disks within 40 patients via magnetic resonance imaging according to the Pfirrmann and Suzuki classification. The degree of disk degeneration was evaluated by two independent musculoskeletal radiologists. After 6 months, the classification was reassessed to evaluate the intraobserver reliability. The inter- and intraobserver reliabilities were then calculated using Cohen's kappa.
RESULTS
The inter- and intraobserver reliability provided a significant agreement between all ratings in Pfirrmann as well as the Suzuki classification (p>0.001). The interobserver reliability was determined to be fair in both the Suzuki classification (κ=0.290) and the Pfirrmann classification (κ=0.265). The intraobserver reliability was substantial in the Suzuki classification (κ=0.798), while it was almost perfect in the Pfirrmann classification (κ=0.858).
CONCLUSIONS
Although not designed for the evaluation of cervical disk degeneration, the Pfirrmann classification yielded equal inter- and higher intraobserver reliability. Both classification systems are viable options for the grading of cervical disk degeneration. While the Pfirrmann classification has the advantage of being better established, the Suzuki classification may be clinically superior due to a better representation of cervical disk degeneration and the consideration of disk bulging for the classification of cervical disk degeneration.
PubMed: 34966859
DOI: 10.22603/ssrr.2021-0048 -
Antimicrobial Resistance and Infection... 2016We assessed the validity of testing for antimicrobial susceptibility of clinical and mutant (GC) isolates by disk diffusion in comparison to agar dilution, and Etest®...
BACKGROUND
We assessed the validity of testing for antimicrobial susceptibility of clinical and mutant (GC) isolates by disk diffusion in comparison to agar dilution, and Etest® (bioMerieux, France), respectively, for three third generation extended spectrum cephalosporins (ESC): ceftriaxone (CRO), cefixime (CFX), and cefpodoxime (CPD).
METHODS
One hundred and five clinical isolates and ten laboratory-mutants were tested following Clinical Laboratory Standard Institute (CLSI) and manufacturer's standards for each of the three methods. The measured diameters by the disk diffusion method were tested for correlation with the MIC values by agar dilution. In addition, comparisons with the Etest® were made. Categorical results for concordance, based on standard CLSI cutoffs, between the disk diffusion and the other two methods, respectively, were tested using the Chi-square statistics. Reproducibility was tested for CFX across a 6-month interval by repeated disk tests.
RESULTS
Across all 115 specimens, the disk diffusion tests produced good categorical agreements, exhibiting concordance of 93.1%, 92.1%, and 90.4% with agar dilution and 93.0%, 92.1%, and 90.4% with Etest®, for CRO, CFX, and CPD, respectively. Pearson correlations between disk-diffusion diameters and agar dilution MIC's were -0.59, -0.67, and -0.81 for CRO, CFX, and CPD, respectively. The correlations between disk diffusion and Etest® were -0.58, -0.73, and -0.49. Pearson correlation between the CFX disk readings over a 6-month interval was 91%.
CONCLUSIONS
Disk diffusion tests remain to be a useful, reliable and fast screening method for qualitative antimicrobial susceptibility testing for ceftriaxone, cefixime, and cefpodoxime.
PubMed: 27904747
DOI: 10.1186/s13756-016-0148-x -
Journal of Spine Research and Surgery 2023Intervertebral disk degeneration (IDD) is an intricate pathological process contributing to one of the major causes of low back pain. The degradation of the...
Intervertebral disk degeneration (IDD) is an intricate pathological process contributing to one of the major causes of low back pain. The degradation of the extracellular matrix (ECM), inflammation, and apoptosis have all been investigated as critical factors involved in the pathology of degenerative disk disease. Additionally, the presence of aberrant microRNAs (miRNAs), conserved molecules that regulate the amount protein post-transcriptionally, may play a crucial role in the pathogenesis of IDD. Research regarding the dysfunction of miRNAs in IDD has been well researched over the past five years. Here, we provide a critical overview of the current knowledge of miRNAs, emphasizing the processes involved in the degenerative disk pathology.
PubMed: 36777190
DOI: 10.26502/fjsrs0051 -
Proceedings of the National Academy of... Jun 2024Magmatic iron-meteorite parent bodies are the earliest planetesimals in the Solar System, and they preserve information about conditions and planet-forming processes in...
Magmatic iron-meteorite parent bodies are the earliest planetesimals in the Solar System, and they preserve information about conditions and planet-forming processes in the solar nebula. In this study, we include comprehensive elemental compositions and fractional-crystallization modeling for iron meteorites from the cores of five differentiated asteroids from the inner Solar System. Together with previous results of metallic cores from the outer Solar System, we conclude that asteroidal cores from the outer Solar System have smaller sizes, elevated siderophile-element abundances, and simpler crystallization processes than those from the inner Solar System. These differences are related to the formation locations of the parent asteroids because the solar protoplanetary disk varied in redox conditions, elemental distributions, and dynamics at different heliocentric distances. Using highly siderophile-element data from iron meteorites, we reconstruct the distribution of calcium-aluminum-rich inclusions (CAIs) across the protoplanetary disk within the first million years of Solar-System history. CAIs, the first solids to condense in the Solar System, formed close to the Sun. They were, however, concentrated within the outer disk and depleted within the inner disk. Future models of the structure and evolution of the protoplanetary disk should account for this distribution pattern of CAIs.
PubMed: 38805273
DOI: 10.1073/pnas.2306995121 -
Intestinal Research Jul 2023The inflammatory bowel disease (IBD)-disk is a validated, visual, 10-item, self-administered questionnaire used to evaluate IBD-related disability. The present study...
BACKGROUND/AIMS
The inflammatory bowel disease (IBD)-disk is a validated, visual, 10-item, self-administered questionnaire used to evaluate IBD-related disability. The present study aimed to evaluate IBD-disk in assessment of IBD daily life burden and its relation with disease activity.
METHODS
A cross-sectional study was conducted between June 2021 and December 2021. Patients with IBD were asked to complete the IBD-disk and a visual analogue scale of IBD daily-life burden (scored from 0-10, score >5 indicative of high burden). The internal consistency of IBD-disk, correlation with IBD daily life burden and disease activity (assessed by partial Mayo score and Harvey Bradshaw Index in patients with ulcerative colitis [UC] and Crohn's disease [CD], respectively) and diagnostic performance of IBD-disk to detect high burden were analyzed.
RESULTS
Out of the 546 patients (mean age 40.33±13.74 years, 282 [51.6%] males) who completed the IBD-disk, 464 (84.98%) had UC and the remaining (n=82, 15.02%) had CD. A total of 311 patients (291 UC and 20 CD; 56.95%) had active disease. The mean IBD-disk total score and IBD daily life burden were 18.39±15.23 and 2.45±2.02, respectively. The IBD-disk total score correlated strongly with the IBD daily life burden (ρ=0.94, P<0.001), moderately with partial Mayo score (ρ=0.50) and weakly with Harvey Bradshaw Index (ρ=0.34). The IBD-disk total score >30 predicted high IBD daily-life burden.
CONCLUSIONS
The IBD-disk accurately predicts the daily life burden and parallels disease activity in patients with IBD and can be applied in clinical practice. (Intest Res, Published online).
PubMed: 36245342
DOI: 10.5217/ir.2022.00037