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Clinical Physiology and Functional... Nov 2021The present study examined cross-sectional and longitudinal relationships between total and segmental subcutaneous tissue thicknesses from ultrasonography (US) and total...
The present study examined cross-sectional and longitudinal relationships between total and segmental subcutaneous tissue thicknesses from ultrasonography (US) and total and segmental fat mass (FM) estimates from dual-energy X-ray absorptiometry (DXA). Traditional US FM estimates were also examined. Twenty resistance-trained males (mean ± SD; age: 22.0 ± 2.6 years; body mass: 74.8 ± 11.5 kg; DXA fat: 17.5 ± 4.5%) completed a 6-week supervised resistance training programme while consuming a hypercaloric diet. Pre- and post-intervention body composition was assessed by DXA and B-mode US. Data were analysed using Pearson's correlation (r), Lin's correlation coefficient (CCC), paired t-tests, Wilcoxon signed-rank tests and Bland-Altman analysis, as appropriate. Cross-sectionally, correlations were observed between total DXA FM and total subcutaneous tissue thickness (r = 0.88). Longitudinally, a correlation was observed between total DXA FM changes and total subcutaneous tissue changes (r = 0.49, CCC = 0.38). Correlations of similar magnitudes were observed for the upper body and trunk estimates, but DXA FM changes were unrelated to subcutaneous tissue changes for the lower body and arms. Cross-sectionally, US 2-compartment FM and DXA FM were correlated (r = 0.91, CCC = 0.83). Longitudinally, a weaker correlation was observed (r = 0.47, CCC = 0.33). In summary, longitudinal associations between US and DXA are weaker than cross-sectional relationships; additionally, correlations between US subcutaneous tissue and whole-body DXA FM appear to be driven by the trunk region rather than appendages. Reporting raw skinfold thicknesses rather than FM estimates alone may improve the utility of techniques based on subcutaneous tissue thickness, such as US and skinfolds.
Topics: Absorptiometry, Photon; Adipose Tissue; Adult; Body Composition; Electric Impedance; Humans; Male; Skinfold Thickness; Subcutaneous Fat; Young Adult
PubMed: 34549507
DOI: 10.1111/cpf.12727 -
Ophthalmology Science Sep 2023To investigate the relationship between retinal traction force and impairment of the inner retinal layer in patients with epiretinal membrane (ERM).
PURPOSE
To investigate the relationship between retinal traction force and impairment of the inner retinal layer in patients with epiretinal membrane (ERM).
DESIGN
Nonrandomized, retrospective consecutive case series.
PARTICIPANTS
Two hundred nine eyes of 201 patients with idiopathic ERM who underwent vitrectomy for idiopathic ERM were enrolled.
METHODS
Retinal folds caused by ERM were visualized using en face OCT, and the maximum depth of retinal folds within the parafovea (MDRF) was measured. Focal macular electroretinogram (ERG) was used to measure the amplitude and implicit time of each component for the ERM eyes and the normal fellow eyes. B-scan OCT images were used to measure the thicknesses of the inner nuclear layer (INL) and outer nuclear layer (ONL) + outer plexiform layer (OPL). Expression of α-smooth muscle actin (α-SMA) in surgically removed ERM specimens was quantified by reverse-transcription polymerase chain reaction.
MAIN OUTCOME MEASURES
We analyzed the relationship between MDRF and the relative amplitudes of focal macular ERG (affected eye/fellow eye), the relationships between MDRF and the mean INL thickness and ONL+OPL thickness, comparison of INL thickness and ONL+OPL thickness for each area when cases were classified according to MDRF localization in the ETDRS chart, and the relationship between MDRF and the relative expression of α-SMA in the ERM specimens.
RESULTS
The MDRF significantly correlated with the relative amplitudes (affected eye/fellow eye) of b-waves and oscillatory potentials (r = -0.657, = 0.015; r = -0.569, = 0.042, respectively) and the mean INL thickness and ONL+OPL thickness (r = 0.604, < 0.001; r = 0.210, = 0.007, respectively). However, only the INL thickness progression rate was significantly correlated with the MDRF progression rate (r = 0.770, < 0.001). On case stratification by localization of MDRF based on the ETDRS chart, in regions other than temporal regions, the INL thickness was significantly greater in regions with MDRF than in other regions. The MDRF significantly correlated with α-SMA expression in the ERM specimens (r = 0.555, = 0.009).
CONCLUSIONS
The findings suggest that ERM impairs the inner retinal layer in a traction force-dependent manner.
FINANCIAL DISCLOSURES
The author(s) have no proprietary or commercial interest in any materials discussed in this article.
PubMed: 37214764
DOI: 10.1016/j.xops.2023.100312 -
Eye (London, England) Feb 2023To determine the distribution of central corneal thickness (CCT) and its determinants in an Iranian geriatric population.
PURPOSE
To determine the distribution of central corneal thickness (CCT) and its determinants in an Iranian geriatric population.
METHODS
This population-based study was conducted in 2019 in Tehran, the capital of Iran, using stratified multistage random cluster sampling. The study population was all residents ≥60 years of age. First, preliminary optometric and ocular health examinations were performed including the measurement of uncorrected and best-corrected visual acuity, objective and subjective refraction, anterior and posterior segment examination. The study participants then underwent corneal imaging using Pentacam HR.
RESULTS
Out of 3791 invitees, 3310 participated in this study (response rate: 87.3%). The mean CCT and apex corneal thicknesses were 528 µ (95% CI: 526-529) and 529 µ (95% CI: 527-530), respectively. The highest and lowest mean corneal thickness was related to the superior (620 µ: 95% CI: 618-622) and the temporal (591 µ: 95% CI: 590-592) paracentral points, respectively. According to the multiple linear regression model, the CCT was significantly inversely related to keratometry readings (K1 and K2) and had a statistically significant direct relationship with intraocular pressure (IOP), corneal eccentricity (ECC), and corneal volume (CV) (all p values <0.05). The CCT was significantly higher in diabetic patients (p = 0.043).
CONCLUSION
The CCT values in the geriatric Iranian population were lower than the values reported in most previous studies. The CCT is mostly influenced by IOP and corneal parameters (curvature, shape factor, and volume) and is not affected by demographic factors, refractive error, and ocular biometric components.
Topics: Aged; Humans; Iran; Intraocular Pressure; Cornea; Tonometry, Ocular; Refractive Errors
PubMed: 35102248
DOI: 10.1038/s41433-022-01946-2 -
Journal of Orthopaedic Trauma Sep 2021The purpose of this study was to determine if the thickness of splint padding could be determined on X-rays, and whether increasing layers of splint padding have an...
OBJECTIVES
The purpose of this study was to determine if the thickness of splint padding could be determined on X-rays, and whether increasing layers of splint padding have an effect on temperature at the skin after placement.
METHODS
Both in vitro and in vivo testing was performed. Ten cadaveric lower extremities were used. A thermocouple was placed on the posterior calf for temperature determination. Cadavers were used with short leg posterior splints with sidebars placed using various thicknesses of padding: (1) 2 layers of Webril, (2) 4 layers of Webril, (3) 2 × 2 padding (Webril followed by kerlix, then repeated), and (4) bulky cotton padding. A splint with no padding was used as a control. Lateral X-rays of the ankle were obtained. The padding thickness was measured. The change in temperature at the level of the skin was measured throughout the process. The test was then repeated in vivo to correlate the cadaver findings with a live subject.
RESULTS
The mean thickness of the 5 padding types could be reliably determined on X-ray. Our cadaver temperature data shows that all padding thickness tested decreased temperature change after plaster curing, with no significant difference between wraps. Live subject testing showed similarities between the 2-layer Webril and 2 × 2 padding, and between the 4-layer Webril and bulky padding.
CONCLUSIONS
Padding thickness can be consistently determined on X-ray. We determined that at least 2 layers of Webril significantly decrease temperature change at the level of the skin caused by plaster curing. Two layers of Webril can be identified on X-ray by measuring at least 1 mm of padding.
Topics: Casts, Surgical; Humans; Splints; Temperature; X-Rays
PubMed: 33512858
DOI: 10.1097/BOT.0000000000002051 -
BioMed Research International 2022Recently, dentists can utilize three-dimensional printing technology in fabricating dental restoration. However, to date, there is a lack of evidence regarding the...
BACKGROUND
Recently, dentists can utilize three-dimensional printing technology in fabricating dental restoration. However, to date, there is a lack of evidence regarding the effect of printing layer thicknesses and postprinting on the mechanical properties of the 3D-printed temporary restorations with the additive manufacturing technique. So, this study evaluated the mechanical properties of a 3D-printed dental resin material with different printing layer thicknesses and postprinting methods.
METHODS
210 specimens of a temporary crown material (A2 EVERES TEMPORARY, SISMA, Italy) were 3D-printed with different printing layer thicknesses (25, 50, and 100 m). Then, specimens were 3D-printed using DLP technology (EVERES ZERO, DLP 3D printer, SISMA, Italy) which received seven different treatment conditions after printing: water storage for 24 h or 1 month, light curing or heat curing for 5 or 15 minutes, and control. Flexural properties were evaluated using a three-point bending test on a universal testing machine (ISO standard 4049). The Vickers hardness test was used to evaluate the microhardness of the material system. The degree of conversion was measured using an FT-IR ATR spectrophotometer. Statistical analysis was performed using two-way analysis of variance (ANOVA) and Tukey's honestly significant difference (HSD) test ( ≤ 0.05).
RESULTS
The 100 m printing layer thickness had the highest flexural strength among the other thickness groups. As a combined effect printing thickness and postprinting conditions, the 100 m with the dry storage group has the highest flexural strength among the tested groups (94.60 MPa). Thus, the group with 100 m thickness that was heat cured for 5 minutes (HC 5 min 100 m) has the highest VHN value (VHN = 17.95). Also, the highest mean DC% was reported by 50 m layer thickness (42.84%).
CONCLUSIONS
The thickness of the 100 m printing layer had the highest flexural strength compared to the 25 m and 50 m groups. Also, the postprinting treatment conditions influenced the flexural strength and hardness of the 3D-printed resin material.
Topics: Flexural Strength; Hardness; Humans; Materials Testing; Printing, Three-Dimensional; Resins, Plant; Spectroscopy, Fourier Transform Infrared; Surface Properties
PubMed: 35237691
DOI: 10.1155/2022/8353137 -
Scientific Reports Jan 2021Current descriptions of retinal thickness across normal age cohorts are mostly limited to global analyses, thus overlooking spatial variation across the retina and...
Current descriptions of retinal thickness across normal age cohorts are mostly limited to global analyses, thus overlooking spatial variation across the retina and limiting spatial analyses of retinal and optic nerve disease. This retrospective cross-sectional study uses location-specific cluster analysis of 8 × 8 macular average grid-wise thicknesses to quantify topographical patterns and rates of normal, age-related changes in all individual retinal layers of 253 eyes of 253 participants across various age cohorts (n = 23-69 eyes per decade). Most retinal layers had concentric spatial cluster patterns except the retinal nerve fibre layer (RNFL) which displayed a nasal, asymmetric radial pattern. Age-related thickness decline mostly occurred after the late 4th decade, described by quadratic regression models. The ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), and outer nuclear layer + Henle's fibre layer (ONL) were significantly associated with age (p < 0.0001 to < 0.05), demonstrating similar rates of thickness decline (mean pooled slope = - 0.07 µm/year), while the IS/OS had lesser mean pooled thickness slopes for all clusters (- 0.04 µm/year). The RNFL, OPL, and RPE exhibited no significant age-related thickness change, and the RNFL were significantly associated with sex. Analysis using spatial clusters compared to the ETDRS sectors revealed more extensive spatial definition and less variability in the former method. These spatially defined, clustered normative data and age-correction functions provide an accessible method of retinal thickness analysis with more spatial detail and less variability than the ETDRS sectors, potentially aiding the diagnosis and monitoring of retinal and optic nerve disease.
Topics: Adult; Aged; Aging; Cluster Analysis; Cross-Sectional Studies; Female; Humans; Male; Middle Aged; Optic Nerve Diseases; Regression Analysis; Retina; Retinal Diseases; Retrospective Studies; Sex Characteristics; Tomography, Optical Coherence; Young Adult
PubMed: 33436715
DOI: 10.1038/s41598-020-79424-6 -
International Ophthalmology Jan 2020The aim of the study was to evaluate the lamina cribrosa (LC) thickness, LC depth, and retinal nerve fiber layer (RNFL) thickness, in migraine patients with and without... (Observational Study)
Observational Study
PURPOSE
The aim of the study was to evaluate the lamina cribrosa (LC) thickness, LC depth, and retinal nerve fiber layer (RNFL) thickness, in migraine patients with and without aura, by using optical coherence tomography (OCT).
METHODS
This single-center, case-control study included 27 migraine with aura (Group I), 35 migraine patients without aura (Group II), and 35 healthy controls (Group III). In only the right eyes of participants, RNFL thickness in all quadrants was analyzed via OCT, whereas LC thickness and depth were measured by enhanced depth imaging OCT.
RESULTS
The mean age and sex distributions did not differ significantly across the groups (p = 0.460 and p = 0.941). The RNFL thickness was significantly lower in Group I (average and superotemporal, superonasal, and inferotemporal quadrants) and Group II (average and superotemporal and superonasal quadrants) when compared with Group III. Disease duration was significantly correlated with RNFL thickness on average and in all quadrants except in the superonasal quadrant in Groups I and II. Patients in Groups I and II had significantly thinner LC thicknesses and deeper LC depth than healthy participants in Group III.
CONCLUSIONS
The LC and RNFL thicknesses were thinner and the LC depth was deeper in migraine patients with or without aura than in healthy individuals, and disease duration correlated significantly with RNFL thickness. Both results suggest that migraine patients are at risk of developing glaucoma.
Topics: Adult; Cross-Sectional Studies; Eye Diseases; Female; Humans; Male; Migraine Disorders; Nerve Fibers; Optic Disk; Prospective Studies; Retinal Ganglion Cells; Risk Factors; Tomography, Optical Coherence
PubMed: 31432353
DOI: 10.1007/s10792-019-01160-2 -
International Journal of Ophthalmology 2021To develop a classifier for differentiating between healthy and early stage glaucoma eyes based on peripapillary retinal nerve fiber layer (RNFL) thicknesses measured...
AIM
To develop a classifier for differentiating between healthy and early stage glaucoma eyes based on peripapillary retinal nerve fiber layer (RNFL) thicknesses measured with optical coherence tomography (OCT), using machine learning algorithms with a high interpretability.
METHODS
Ninety patients with early glaucoma and 85 healthy eyes were included. Early glaucoma eyes showed a visual field (VF) defect with mean deviation >-6.00 dB and characteristic glaucomatous morphology. RNFL thickness in every quadrant, clock-hour and average thickness were used to feed machine learning algorithms. Cluster analysis was conducted to detect and exclude outliers. Tree gradient boosting algorithms were used to calculate the importance of parameters on the classifier and to check the relation between their values and its impact on the classifier. Parameters with the lowest importance were excluded and a weighted decision tree analysis was applied to obtain an interpretable classifier. Area under the ROC curve (AUC), accuracy and generalization ability of the model were estimated using cross validation techniques.
RESULTS
Average and 7 clock-hour RNFL thicknesses were the parameters with the highest importance. Correlation between parameter values and impact on classification displayed a stepped pattern for average thickness. Decision tree model revealed that average thickness lower than 82 µm was a high predictor for early glaucoma. Model scores had AUC of 0.953 (95%CI: 0.903-0998), with an accuracy of 89%.
CONCLUSION
Gradient boosting methods provide accurate and highly interpretable classifiers to discriminate between early glaucoma and healthy eyes. Average and 7-hour RNFL thicknesses have the best discriminant power.
PubMed: 33747815
DOI: 10.18240/ijo.2021.03.10 -
Frontiers in Medicine 2021To evaluate the effect of femtosecond laser-assisted keratomileusis (FS-LASIK) on retinal fovea thickness, volume, and retinal nerve fibre layer (RNFL) thickness....
To evaluate the effect of femtosecond laser-assisted keratomileusis (FS-LASIK) on retinal fovea thickness, volume, and retinal nerve fibre layer (RNFL) thickness. Thirty-seven eyes (37 patients) undergoing FS-LASIK were included in this prospective study. Optical coherence tomography (OCT) was performed 1 day before, 1 h and 1 day after FS-LASIK surgery. Eighteen male and nineteen females were enrolled. Mean patient age was 22.94 ± 4.22 years. One hour postoperatively, macula fovea thicknesses, macula fovea volume, macula parafovea thickness, macula parafovea volume, macula perifovea thickness, macula perifove volume, temporal RNFL thickness, and superior RNFL thickness measures showed significant decrease ( = 6.171, 6.032, and 9.837, 9.700, 2.532, 4.393, 4.926, 2.265; = 0.000, 0.000, 0.000, 0.000, 0.016, 0.000, 0.000, and 0.011). Day 1 post-operation, macula fovea thicknesses, macula fovea volume, macula parafovea thickness, macula parafovea volume, and inferior RNFL thickness measures showed significant change compared to preoperative measures ( = 3.620, 3.220, 2.901, 2.910, 3.632; = 0.001, 0.003, 0.006, 0.006, and 0.001). Our data suggest there are alterations in retinal foveal and RNFL measurements by OCT 1 h and 1 day after FS-LASIK surgery.
PubMed: 34912833
DOI: 10.3389/fmed.2021.778666 -
BMC Oral Health Feb 2023The aim of this study was to compare the pushout bond strength (POBS) of three hydraulic cements, when used at thicknesses of 3 and 5 mm.
BACKGROUND
The aim of this study was to compare the pushout bond strength (POBS) of three hydraulic cements, when used at thicknesses of 3 and 5 mm.
METHODS
78 root slices of 3 and 5 mm of thickness were obtained from human teeth. Cylindrical cavities of 1.4 mm of diameter were drilled and filled with Biodentine (BD), Totalfill Root Repair paste (TF) or ProRoot MTA White (PMTA). Pushout tests were performed 21 days later. The fracture pattern of each sample was also analyzed. POBS data were analyzed with Welch and Brown-Forsythe and Tamhane's post hoc tests and a Weibull analysis was also performed.
RESULTS
In the 3 mm group, TF showed significantly lower bond strength than BD and PMTA. In the 5 mm group, BD showed significantly higher bond strength than TF. Both BD and TF showed higher bond strength when the thickness of the sample increased, while PMTA did not.
CONCLUSIONS
TF and BD achieve higher pushout bond strength resistance when used at a thickness of 5 mm than at 3 mm, while the mean resistance of PMTA is less influenced by the thickness. At 5 mm of thickness, BD and PMTA exhibit similar resistance to displacement. However, the behavior of BD is more predictable than that of its predecessor. BD is a reliable hydraulic cement for clinical situations where thick cavities need to be filled and displacement resistance plays an important role. Clinicians need to consider choosing specific hydraulic cements according to the thickness of material to be used.
Topics: Humans; Calcium Compounds; Dental Cements; Dental Cementum; Silicates; Dental Bonding; Materials Testing
PubMed: 36750823
DOI: 10.1186/s12903-023-02758-w